}.  j :, ..       jo. 


D    C  SLATE 


• 


WOODEN  BOX 

AND 

CRATE  CONSTRUCTION 


PREPARED  BY 
FOREST  PRODUCTS  LABORATORY 

U.  8.  DEPARTMENT  OF  AGRICULTURE 

FOREST  SERVICE 
MADISON,  WISCONSIN 


PUBLISHED  BY 

NATIONAL  ASSOCIATION  OF  BOX  MANUFACTURERS 

1553  CONWAY  BUILDING 

CHICAGO,  ILLINOIS 

1921 


c 


IV  3 


AGRIC,  DEPL 


Main 


PUBLISHER'S  INTRODUCTION 

The  National  Association  of  Box  Manufacturers  is  an 
organization  of  the  leading  manufacturers  of  wooden  boxes 
of  every  section  of  the  country.  Many  of  its  members  also 
make  other  types  or  kinds  of  boxes,  but  the  association  con- 
fines its  activities  to  the  interests  of  the  wooden  box. 

The  association  aims  to  promote  all  projects  of  genuine 
interest  to  its  members ;  to  obtain  a  unity  of  action  in  mat- 
ters affecting  the  wooden  box  industry ;  to  advertise  properly 
the  merits  of  wooden  boxes,  and  to  be,  in  fact,  a  constructive 
influence  in  the  improvement  of  conditions  in  the  industry 
and  better  service  for  consumers.  And  by  the  same  token 
the  association  stands  guard  against  any  project  or  practice 
which  may,  in  any  way, -bring  wooden  box  service  into  dis- 
favor or  disrepute. 

The  association  believes  in  the  scientific  construction  of 
packing  boxes.  It  believes  that  the  dissemination  of  knowl- 
edge among  box  users,  as  well  as  manufacturers,  as  to  what 
has  already  been  accomplished  and  what  is  now  being  done 
along  the  lines  of  scientific  research  in  box  construction,  is 
to  the  mutual  advantage  of  all.  Such  knowledge  enlarges  the 
field  of  usefulness  of  the  wooden  box,  and  leads  to  conserva- 
tion of  material  and  lowering  of  costs,  all  of  which  tends  to 
stabilize  the  use  of  wooden  boxes,  and  the  business  of  the 
manufacturer.  This  is  the  reason  for  publishing  this  book. 

The  book  includes,  in  a  general  way,  all  the  latest  and 
mast  accurate  information  available  on  box  and  crate  design. 
However,  details  applicable  to  different  kinds  of  boxes  for 
carrying  special  commodities  vary  with  each  commodity, 
hence  the  application  of  the  fundamental  principles  discussed 
in  this  book  must  be  made  by  each  manufacturer  and  indi- 
vidual user  of  such  boxes,  except,  of  course,  as  the  principles 
apply  to  boxes  which  have  already  been  standardized  as  to 
specifications. 

Standardization  of  boxes  and  crates  is  a  recognized  aim 
of  the  association.  Many  packages  have  already  been  stand- 
ardized and  many  others  are  being  studied  with  a  view  to 
standardization. 


458422 


VI 

Much  valuable  information  on  boxes  for  carrying  certain 
commodities  has  been  obtained  as  a  result  of  these  studies. 
No  attempt  has  been  made  to  include  that  information  in  this 
book,  but  it  is  available  and  will  be  freely  given  to  those  who 
have  need  for  it. 

A.11  of  the  machinery  of  the  association  is  at  the  service 
of  the  public  in  any  matters  pertaining  to  the  development  of 
better  packing  methods  or  in  solving  any  packing  problem. 

THE  NATIONAL  ASSOCIATION 
OF  Box  MANUFACTURERS. 

1553   Conway   Building. 
Chicago,  Illinois, 
March    1,    1921. 


INTRODUCTION 

The  Forest  Products  Laboratory  is  a  research  unit  of  the 
Forest  Service,  U.  S.  Department  of  Agriculture.  It  is  located 
at  Madison,  Wisconsin,  where  it  was  established  in  1910  in 
co-operation  with  the  University  of  Wisconsin.  Its  purpose 
is  to  acquire,  disseminate  and  apply  useful  knowledge  of  the 
properties,  uses  and  methods  of  utilization  of  all  forest  prod- 
ucts and  thereby  to  promote  economy  and  efficiency  in  the 
processes  by  which  forests  are  converted  into  commercial 
products.  In  this  work  220  research  technologists  are  em- 
ployed. Its  field  of  investigations  and  activities  embraces : 

1.  Obtaining  authoritative  information  on  the  mechanical 
and  physical  properties  of  commercial  woods  and  products 
derived  from  them ; 

2.  Studying  and  developing  the  fundamental  principles 
underlying  the   seasoning  and  kiln-drying  of  wood,   its  pre- 
servative treatment,  its  use  for  the  production  of-  fiber  prod- 
ucts (pulp,  paper,  fiber  board,  etc.),  and  its  use  in  the  manu- 
facture of  alcohol,  turpentine,  rosin,  tar  and  other  chemically 
derived  products ; 

3.  Developing  practical  ways  and  means  of  using  wood 
which,  under  present  conditions,  is  being  wasted ; 

4.  Co-operating  with  consumers  of  forest  products  in  im- 
proving present  methods  of  use ;  also  in  formulating  specifi- 
cations and  grading  rules  for  commercial  woods,  and  materials 
obtained  from  them,  and  for  material  used  in  the  preservative 
treatment  of  wood ;  and 

5.  Making  the  information  obtained  available  to  the  pub- 
lic through  publications,  correspondence,  and  by  other  means. 

Commercial  research  and  mechanical  tests  on  containers 
were  begun  in  1915  in  co-operation  with  the  National  Associa- 
tion of  Box  Manufacturers,  the  National  Canners'  Associa- 
tion, and  the  National  Wholesale  Grocers'  Association. 
Methods  of  testing  and  testing  equipment  were  developed 
which  have  since  become  more  or  less  standard  for  the  box 
industry.  From  the  data  accumulated  by  the  laboratory,  the 
War  Department  prepared  during  the  war  general  specifica- 

vii 


Vlll 


tions  for  overseas  containers.  At  the  laboratory  in  Madison, 
many  containers  to  be  used  for  the  shipment  of  war  equipment 
were  tested  and  redesigned  along  more  economical  lines,  in- 
cluding increase  in  strength,  decrease  in  amount  of  material 
required,  decrease  in  cubic  contents  and  a  consequent  reduc- 
tion of  ocean  freight  costs. 

Since  the  war  the  laboratory  has  co-operated  with  many 
associations  and  companies  in  testing  and  studying  the  con- 
struction of  many  different  types  of  containers  such  as  those 
used  for  the  shipment  of  electric  lamps,  cream  separators, 
small  tractors,  talking  machines,  boiler  castings,  furniture, 
paints  and  oils,  piano  benches,  fruit  baskets  and  crates,  and 
shoes. 


CONTENTS 

PAGE 

PUBLISHER'S  INTRODUCTION    v 

INTRODUCTION  vii 

LIST  OF  TABLES xiv 

LIST  OF   PLATES xiv 

LIST    OF    FIGURES xv 

CHAPTER  I 

Use  of  Wood  in  Box  and  Crate  Construction 

Adaptability     1 

Availability     1 

Cost    1 

Salvage  value    1 

Qualities    2 

Desirable    qualities    2 

KINDS  AND  AMOUNTS  OF  LUMBER  USED 2 

The  choice  of  species 2 

Amount  of   each   kind   of    lumber   used 3 

Consumption  of  box  lumber  by  States 5 

Distribution   of   box  lumber 5 

COMMERCIAL    GRADES    AND    SIZES    OF    LUMBER    AVAILABLE    FOR    Box 

.CONSTRUCTION     8 

Standard  Defects  and  Blemishes  in  Lumber 8 

Grading  According  to  Size  of  Lumber  10 

Standard    sizes    of    lumber 10 

Grades  suitable  for  boxes  and  crates 11 

IMPORTANT  PHYSICAL  PROPERTIES  OF  WOOD  WHICH  INFLUENCE  ITS  USE 

IN    Box   CONSTRUCTION    14 

Weight     14 

Importance 14 

How  the  weight  of  lumber  is  expressed '  14 

Factors  Which  Influence  the  Weight  of  Lumber 14 

Species     14 

Density,  or  amount  of  wood  substance 15 

Moisture  content 15 

Resin    content    .- 15 

Moisture  Content   15 

Importance    15 

How  determined   15 

Variation     16 

How  the  moisture  is  contained  in  wood 16 

Proper  moisture  content  of  box  lumber    17 

Shrinking  and  Swelling  of  Wood  22 

Extent    22 

How  Troubles   from   Shrinking  and  Swelling  May  Be  Reduced  to 

a  Minimum  in  Boxes   23 

Checking   25 


x  CONTENTS 

PAGE 

Cupping  25 

Casehardening  25 

Honeycombing 25 

Color  25 

Odor  and  taste 26 

MECHANICAL  OR  STRENGTH  PROPERTIES  OF  WOOD 26 

Meaning  of  strength 26 

Tensile  strength '26 

Compression  strength  26 

Shearing  strength 26 

Strength  as  a  beam 28 

Stiffness 30 

Shock-resisting  ability  30 

Hardness 30 

Nail-holding  power  .' .  .  .  30 

CARE  AND  SEASONING  OF  LUMBER  IN  STORAGE 30 

Possible  Deterioration  in  Stored  Lumber 31 

Checking  at  ends  and  on  surfaces 31 

Twisting  and  cupping 31 

Casehardening,  honeycombing,  and  collapse 31 

Blue  stain  or  sap  stain 31 

Decay  or  rot 31 

Insect  attack  32 

Proper  methods  of  piling  lumber  in  the  yard 32 

Foundations  and  skids 35 

Stickers  35 

Placing  of  lumber 36 

Size  and  spacing  of  piles 36 

Kiln-drying  box  lumber 36 

THE  USE  OF  VENEER  IN  THE  CONSTRUCTION  OF  PACKING  BOXES 37 

Definition  37 

Manufacture  of  Veneer  37 

Alethod  of  cutting 37 

Drying 38 

Woods  Used  for  Box  Veneers  38 

Use  of  plywood  in  packing  boxes 39 

CHAPTER  II 

Box  Design 

FACTORS   INFLUENCING  DETAILS  OF  DESIGN 41 

Lumber    and    Veneer 41 

Availability   and    supply 41 

Cost    42 

Manufacturing  Limitations    42 

Equipment     42 

Cost    of    operation 42 

Styles    of    boxes 42 

Balanced  Construction  and  Factors  Affecting   Strength 43 

Width  of   stock  and  joints 43 

Corrugated   fasteners    45 

Physical  properties  of  wood 45 

Moisture   content    47 

Defects    48 

Nailing  qualities  of  wood 51 

Fastenings   and   reinforcements 53 

Directions    for   nailing 55 


CONTENTS  xi 

PAGE 

Side  nailing 56 

Nails  for  clinching 56 

Large  nail  heads 57 

Overdriving  nails  58 

Screws  59 

Staples 59 

Strapping  and  wire  bindings 60 

Types  of  metal  bindings - 60 

Reinforcements  and  Handles 62 

Corner  irons,  hinges,  and  locks 62 

Battens  62 

Hand-holds  and  handles  62 

CHARACTERISTICS  OF  THE  VARIOUS  STYLES  OF  BOXES 64 

Nailed  boxes 64 

Lock-corner  boxes  66 

Dovetail  boxes  67 

Wirebound  boxes  67 

Panel  boxes  70 

FACTORS  DETERMINING  THE  AMOUNT  OF  STRENGTH  REQUIRED 70 

Contents  70 

Hazards  of  transportation 71 

FACTORS  DETERMINING  THE  SIZE  OF  A  Box 73 

Gross  weight  73 

Desired  quantity  73 

Nesting,  disassembling,  or  knocking  down  contents 73 

Minimum  displacement  73 

Traffic  limitations  74 

SPECIAL  CONSTRUCTIONS  74 

Protection  of  fragile  and  delicate  contents 74 

Vermin  76 

Thieving  ' 76 

CHAPTER  III 

Crate    Design 

FACTORS  AFFECTING  STRENGTH  OF  CRATES   77 

Influence  of  Styles  of  Crates  on  Strength 77 

Types   of   corner   construction 77 

Frame  members    78 

Skids    79 

Bracing    long   crates 79 

Fitting  and   fastening  braces 80 

Scabbing     80 

Shearing    81 

Physical   Properties  of   Wood  Affecting   Strength 81 

Relative  thickness  of  material 81 

Moisture  content    81 

Defects 81 

Nailing  and  bolting  qualities  of  wood 8L 

Fastenings    and    Reinforcements 82 

Nails    and    nailing 82 

Bolts  and  bolting 83 

Lag    screws    84 

Straps     84 

Binding    rods     84 

Internal    bracing    84 


xii  CONTENTS 

PAGE 

FACTORS  DETERMINING  AMOUNT  OF  STRENGTH   REQUIRED  IN  CRATES..  85 

Hazards  of  Transportation   85 

FACTORS  INFLUENCING  THE  SIZE  OF  CRATES 86 

CHAPTER  IV 
Box  and  Crate  Testing 

METHODS  OF  TESTING  AND  THEIR  SIGNIFICANCE 87 

Drum    Test    91 

Drop   Tests    92 

Drop-cornerwise  test   92 

Drop-edgewise   test    92 

Compression    Tests    92 

Compression-on-an-edge    test    92 

Compression-cornerwise    test    96 

Compression-on-faces  test 96 

Supplementary   Tests    96 

CHAPTER  V 
Box  and   Crate  Specifications 

Purpose     97 

STANDARDIZATION   OF   PACKING    BOXES 98 

GENERAL    SPECIFICATIONS    FOR    WOODEN    BOXES,    NAILED    AND    LOCK- 
CORNER   CONSTRUCTION    99 

Material     99 

Grouping  of  Woods    100 

Thickness  of  Lumber   100 

Thickness   of   parts 100 

Width  of  parts : 101 

Surfacing    101 

Joining     101 

Schedule  of  Nailing   101 

Size  of  nails   101 

Spacing  of  nails    102 

SPECIFIC   SPECIFICATIONS  FOR   NAILED  AND  LOCK-CORNER   BOXES 103 

Canned   Food   Cases 103 

GENERAL  SPECIFICATIONS  FOR  4-ONE  AND  SIMILAR  BOXES 103 

General    form    104 

Grouping  of  woods    104 

Materials    105 

Cleats     105 

Thin  boards    105 

Staples     105 

Assembling    105 

Boxes  with  wedgelock  ends    106 

Boxes    with    detached    tops 107 

CHAPTER  VI 

Structure  and  Identification  of  Woods 

STRUCTURE  OF  WOOD  109 

Heartwood   and    Sapwood 109 

Annual  Rings 110 

Springwood   and    Summerwood 110 

The   Structure  of   Hardwoods..                                                                 .  112 


CONTENTS  xiii 

PAGE 

The    Structure   of    Conifers 114 

PROCEDURE  IN   IDENTIFYING  WOOD 115 

KEY   FOR  THE  IDENTIFICATION   OF   WOODS   USED   FOR   Box   AND   CRATE 

CONSTRUCTION    117 

Hardwoods 117 

Conifers     122 

DESCRIPTION  OF  Box  .WOODS  126 

Hardwoods 126 

Ring-porous   woods 126 

Diffuse-porous    woods     128 

Conifers    (non-porous  woods) 132 

GRADING  RULES  FOR  ROTARY  CUT  Box  LUMBER 137 

Other    species    138 

APPENDIX 

NAMES  AND  DESCRIPTION  OF  GRADES  OF  LUMBER  SUITABLE  FOR  PACKING 

BOXES     : 141 

INDEX   .  200 


TABLES 

PAGE 

FACTORS  DETERMINING  AMOUNT  OF  STRENGTH  REQUIRED  IN  CRATES....     85 
TABLE     1. — Box    Woods,    Consumption    by    Box    Manufacturers,    and 

Total    Lumber    Production • 3 

TABLE    2. — Box   Lumber   Consumption   and   Total   Lumber    Production 

by    States    6 

TABLE    3. — Quantities  of  Principal  Woods  Used  Annually  by  Box  and 

Crate  Manufacturers  in  the  Most  Important  States 7 

TABLE  4. — Approximate  Weights  of  Lumber  per  Cubic  Foot,  and  per 
Square  Foot  of  Usual  Thicknesses  Used  in  Packing 
Boxes,  Thoroughly  Air-Dry  (12  to  15  per  cent  moisture), 

and   Estimated   Shipping   Weights    12 

TABLE     5. — Per  Cent  of  Shrinkage  Across  the  Grain 23 

TABLE    6. — Physical  and   Mechanical   Properties   of   Woods   Grown   in 

the  United   States    27 

TABLE    7. — Some  Physical  and  Mechanical   Properties  of   Box  Woods 

on  the  Basis  of   White  Pine 28 

TABLE  8. — Thicknesses  of  Box  Boards  Obtained  by  Resawing  or  Dress- 
ing 4/4  to  7/4-Inch  Lumber 40 

TABLE    9. — Standard    Thicknesses   of    Hardwoods 41 

TABLE  10. — Holding  Power  of  Nails  in  Side  and  End  Grain  of  Various 

Species     5Q 

TABLE  11. — Effect  of  Size  of  Heads  on  Strength  of  a  Nailed  Joint....     Sv 

TABLE  12. — Resistance  to  Withdrawal  of  No.  12  Screws 59 

TABLE  13. — Size  of   Nails   for  Crating 83 

TABLE  14.— Size  of  Bolts  for  Crating 84 

TABLE  15. — Cement-coated  Coolers  or   Standard   Nails  and   Sinkers  or 

Countersunk    Nails    139 

TABLE  16.— Cement-coated    Box    Nails 140 

TABLE  17. — Miscellaneous    Cement-coated    Nails 140 

PLATES 

PLATE  I.. — Defects     recognized     in     the     commercial     grading     of 

lumber    163 

PLATE         II. — Cubes  of  wood  magnified  about  25  diameters 164 

PLATE       III. — Styles   of   wooden   boxes,    nailed   and   lock-corner    con- 
struction       167 

PLATE        IV. — Special    styles    of    boxes 169 

PLATE          V. — Strapped  boxes    171 

PLATE        VI.— Types  of  handles 173 

PLATE      VII. — Different  types  of  corner  construction 175 

PLATE    VIII.— Wirebound   boxes 177 

PLATE        IX. — Types  of  commercial  boxes 179 

PLATE          X. — Types  of  plywood  or  veneer  panel  boxes 181 

PLATE        XL — Three-way  crate  corners 183 

PLATE      XII. — Various  arrangements  of   crate  members   at   three-way 

corner     185 

PLATE    XIII. — Crates  with  special  features 187 

PLATE     XIV. — Method  of   numbering   faces   of   test   boxes   and  crates 
for   convenience    in    recording    data    and    location    of 

failures    189 

PLATE        XV.— Different  kinds  of  joints  and   fasteners 191 

xiv 


xv  CONTENTS 

PAGE 

PLATE     XVI. — Hardwoods   with    pores 193 

PLATE    XVII. — Diffuse-porous  hardwoods   194 

PLATE  XVIII. — Softwoods,  conifers,  or  woods  without  pores  or  vessels  197 
PLATE     XIX. — Split  tangential   surfaces  of   Sitka  spruce  and  Douglas 

fir 198 

FIGURES 

FIG.    1. — Annual  lumber  consumption  by  States  for  the  manufacture  of 

boxes,  crates,  fruit  and  vegetable  packages 4 

FIG.    2. — Relation  of  moisture  content  of  wood  to  relative  humidity. . .     17 
FIG.    3. — Relation  between  the  volumetric  shrinkage  and  specific  gravity 

of  various  American  woods 18 

FIG.    4. — Cupping  of  lumber 20 

FIG.    5. — Effect  of  moisture  upon  the  strength  of  small  clear  specimens 

of  Western  hemlock 21 

FIG.    6. — End  of  honeycombed  oak  plank 23 

FIG.    7. — Collapse   in    1-inch   boards 24 

FIG.    8. — Method  of  measuring  twisting  of  plywood 32 

FIG.    9. — Lumber  piled  sidewise  on  concrete  and  metal  foundations....     33 
FIG.  10. — A  well-kept  lumber  yard  maintained  by  a  large  Eastern  wood- 
using  factory   34 

FIG.  11. — Side   view   of   lumber   piled   endwise   to   the   alley   with   skids 

resting  directly  on  the   piers 34 

FIG.  12. — Effect  of  condition  and  change  of  condition  of  lumber  on 
strength  of  boxes  in  storage.  Boxes  for  2  doz.  No.  3  cans, 
nailed  with  seven  cement-coated  nails  to  each  nailing  edge. .  46 
FIG.  13. — Effect  of  shrinkage  on  strapped  boxes.  Boxes  made  and 
strapped  at  a  30  per  cent  moisture  content ;  the  boxes  were 
photographed  after  drying  out  to  10  per  cent  moisture 

content     47 

FIG.  14. — Division  of  a  beam  into  volumes  for  describing  the  location  of 

knots     48 

FIG.  15. — Broken  crating  of  ornamental  concrete  lighting  post 49 

FIG.  16. — Effect  of  time  on  the  holding  power  of  nails 52 

FIG.  17. — Details    for    nailing    standard    styles    of    boxes    for    domestic 

shipment    54 

FIG.  18. — Relation   of    number   of   nails   to   amount   of    rough   handling 
required  to  cause  loss  of  contents.    Nailed  boxes  for  2  doz. 

No.  3  cans 56 

FIG.  19. — Injury   to   wood   fiber   resulting  from  overdriving  nails 56 

FIG.  20. — Effect    of    overdriving    nails 58 

FIG.  21. — Nailed  box  showing  panel  style  of  construction 69 

FIG.  22. — Box    with    eorrugated    fiber    board  lining  and  cells 75 

FIG.  23.- — Testing  boxes  in   small   revolving  drum  developed  at   Forest 

Products  Laboratory   88 

FIG.  24. — Standard    large    drum    testing    machine    developed    at    Forest 

Products    Laboratory    " 89 

FIG.  25. — Method  of  making  drop-cornerwise  test 90 

FIG.  26. — Method  of  making  compression-on-an-edge  test 93 

FIG.  27. — Method  of  making  compression-cornerwise  test 94 

FIG.  28. — Method  of  making  compression-on-faces  test 95 

FIG.  29. — Section  of  Western  yellow   pine  log    Ill 

FIG.  30.— Forest  regions  of  the  United   States    .125 


WOODEN    BOX  AND  CRATE  CONSTRUCTION 

CHAPTER  I 

THE  USE  OF  WOOD  IN  BOX  AND  CRATE 
CONSTRUCTION 

COMMERCIAL  GRADES  AND  SIZES  OF  LUMBER  AVAILABLE  FOR  Box 
CONSTRUCTION — IMPORTANT  PHYSICAL  PROPERTIES  OF 
WOOD  WHICH  INFLUENCE  ITS  USE  IN  Box  CONSTRUCTION 
— MECHANICAL  OR  STRENGTH  PROPERTIES  OF  WOOD — CARE 
AND  SEASONING  OF  LUMBER  IN  STORAGE — THE  USE  OF 
VENEER  IN  THE  CONSTRUCTION  OF  PACKING  BOXES. 

ADAPTABILITY 

Availability — Although  our  forest  resources  are  rapidly 
diminishing,  lumber  is  still  the  most  abundant  material 
economically  suitable  for  the  manufacture  of  packing  boxes 
and  crates.  The  lower  grades  of  lumber  are  used  almost  ex- 
clusively for  this  purpose  and  are  sure  to  be  abundant  for 
many  years  to  come.  The  closer  utilization  of  virgin  timber, 
especially  of  the  small  and  defective  trees  and  of  the  tops,  and 
the  cutting  of  second  and  third-growth  timber,  which  is 
nearly  always  of  poorer  quality,  make  a  large  amount  of 
low  grade  lumber  available.  Thus,  in  the  eastern  section  of 
the  United  States,  cut-over  or  second-growth  forests  furnish 
the  greater  part  of  the  supply  of  logs,  and  these  logs  furnish 
a  large  amount  of  low  grade  lumber,  so  that  the  percentage 
of  low  grades  manufactured  from  southern  yellow  pine,  hem- 
lock, and  northern  pine  has  increased  rapidly  during  recent 
years. 

Cost — The  large  amount  of  low-grade  lumber  manufac- 
tured has  kept  the  cost  comparatively  low.  And  the  increase 
in  cost  of  rotary-cut  lumber  or  veneer,  caused  by  the  neces- 
sity of  using  better  logs  than  for  other  kinds  of  box  lumber, 
is  offset  by  the  thinness  of  the  material  and  the  compara- 
tively small  waste  in  cutting. 

Salvage  Value — Wooden  packing  boxes  have  consider- 
able salvage  value,  as  is  indicated  by  the  ready  sale  mer- 


2  U'OODEX  BOX   AXD   CRATE   CONSTRUCTION 

chants  have  for  such  material.  Some  large  mercantile  con- 
cerns rebuild  their  used  boxes  to  store  goods  in  or  to  use  for 
shipping  purposes.  Whenever  boxes  are  used  over  again 
for  shipping,  special  precautions  should  be  taken  to  make 
sure  that  they  are  in  lit  condition  for  transportation.  Many 
of  the  claims  for  damaged  freight  are  due  to  the  use  of 
second-hand  boxes  in  imperfect  condition.  Other  purposes 
to  which  used  packing  boxes  are  put  are  commonplace. 
Quite  often  the  box  is  taken  apart  and  the  lumber  used  for 
repairs  or  light  construction  work.  Considerable  kindling  is 
often  obtained  from  the  dump  pile  of  boxes  in  the  merchant's 
back  yard. 

QUALITIES 

Desirable  Qualities — Wood  possesses  the  following 
properties  desirable  in  the  manufacture  and  subsequent  use  of 
packing  boxes  and  crates : 

1.  It  is  strong  for  its  weight. 

2.  It  is  easily  worked. 

3.  It  is  easily  fastened  together. 

4.  It  is  not  easily  indented  or  bent  out  of  shape. 

5.  It  is  not  corroded  by  sea  water  or  attacked  by  acids 
unless  they  are  of  high  concentration. 

6.  It  is  a  poor  conductor  of  heat,  which  is  of  service  in 
protecting  certain  contents  of  packing  boxes  when  stored  for 
a  relatively  short  time  exposed  to  the  sun's  rays,  to  heat  from 
steam  pipes  or  boilers,  or  to  freezing  temperatures. 

7.  It   takes   and   holds   ink  well,   so   that   addresses   and 
advertising  can  be  stenciled  or  printed  on  it  without  difficulty. 

8.  When  its  usefulness  is  ended  and  it  becomes  refuse, 
it  can  be  easily  disposed  of. 

KINDS  AND  AMOUNTS   OF  LUMBER  USED 

The  Choice  of  Species — The  choice  of  species  for  boxes 
and  crates  is  influenced  chiefly  by  cost  and  availability,  the 
tendency  being  usually  to  make  selection  out  of  kinds  of  lum- 
ber that  are  comparatively  cheap  and  readily  available  in  the 
locality  where  the  manufacturing  plant  is  situated ;  but,  in 
addition,  the  degree  in  which  the  desirable  qualities  listed 
above  are  present  is  also  considered,  together  with  re- 
sistance to  shearing  out  of  fastenings  at  the  end  of  boards, 
the  commodities  to  be  packed,  and  the  comparative  freedom 
from  odor  and  taste. 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTOR        3 

TABLE  1.    Box  WOODS,  CONSUMPTION  BY  Box  MANUFACTURERS,  AND  TOTAL 
LUMBER  PRODUCTION 


Kind  of  wood 

Quantity  used 
annually  by  box 
manufacturers 
(1912) 

Total  lumber 
production1 
(1918) 

Feet 
board  measure 

Feet 
board  measure 

White  pine 
Yellow   pine    (including    North    Carolina 
pine) 
Red  gum  (including  sap  gumj 
Spruce  
Western  yellow  pine. 
Cottonwood 
Hemlock.  . 
Yellow  poplar 
Maple 
Birch  
Basswood    . 

1,131,969,940 

1,042,936,123 
401,735,390 
335,935,643 
288,691,927 
210,819,509 
203,526,091 
165,116,737 
96,831,648 
90,787,900 
86,979,611 

2,200,000,000 

10,845,000,000 
765,000,000 
1,125,000,000 
1,710,000,000 
175,000,000 
1,875,000,000 
290,000,000 
815,000,000 
370,000,000 
200,000,000 

Beech 
Tupelo 
Elm. 
Oak  
Balsam  fir 
Cypress 

77,899,280 
74,982,910 
63,726,458 
56,?62,111 
40,173,700 
38  962  895 

290,000,000 
237,000,000 
195,000,000 
2,025,000,000 
82,000,000 
630000000 

Chestnut 

36,216  700 

400000000 

Sugar  pine 
Sycamore 

24,686,000 
16,451,693 

111,800,000 
30000000 

Ash.  . 
Willow 

10,507,308 
10,004,600 

170,000,000 
6,269,000 

Larch  (including  tamarack) 
Douglas  fir.  . 
Noble  fir  
Magnolia  .  . 
Buckeye  
White  fir  
v^CQcH"  
Redwood  .  . 
Red  fir 

All  other  woods  

7,470,300 
7,349,840 
6,653,500 
5,449,000 
3,174,028 
3,142,080 
2,512,150 
2,439,500 
1,328,330 

3,150,278 

355,000,000 
5,820,000,000 
5,201,000 
1,579,000 
3,646,000 
213,000,000 
245,000,000 
443,231,000 
Included  in 
white  fir 
60,963,000 

Total  

4,547.973.180 

31,694,689,000 

Amount  of  Each  Kind  of  Lumber  Used- — The  woods 
used  for  boxes,  the  amounts,  and  the  total  annual  production 
of  lumber  of  each  species  are  given  in  Table  1.  The  figures 
on  the  consumption  of  box  lumber  are  those  secured  by  a 


M^omputed  total  productions.  For  details  see  U.  S.  Department  of  Agriculture 
Bulletin  845,  "Production  of  Lumber,  Lath,  and  Shingles  in  191S." 

The  explanation  of  Tables  1,  2  and  3.  and  the  information  contained  in  Table 
5  were  taken  principally  from  a  mimeographed  circular.  "Packing  Box  Woods  : 
Kinds,  Supply,  Distribution,  Grades  and  Sizes  Available,"  prepared  by  J.  C.  Nellis. 
formerly  Forest  Examiner  in  the  Forest  Service,  U.  S.  Dept.  Agriculture. 


WOODEN   BOX   AND    CRATE   CONSTRUCTION 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON        5 

series  of  studies  of  the  wood-using  industries  by  States,  made 
by  the  Forest  Service  from  1909  to  1913.  The  information, 
however,  is  not  complete  owing  to  the  fact  that  a  number 
of  mills  did  not  report  their  consumption.  It  is  estimated 
that  today  the  amount  of  lumber  used  annually  in  the  manu- 
facture of  shipping  containers  is  between  five  and  six  billion 
feet,  or  nearly  one-sixth  of  the  total  lumber  cut  in  the  United 
States.  While  the  figures  in  the  table  apply  to  different  years, 
all  are  based  on  a  period  of  12  months.  They  may  be  said 
to  apply  to  1912  as  an  average  year. 

The  figures  on  the  total  production  of  different  species 
are  for  1918,  the  latest  available  at  this  time. 

In  compiling  statistics  it  has  been  found  best  to  combine 
some  of  the  different  species  or  kinds  of  woods  because  of 
the  confusion  on  the  part  of  manufacturers  as  to  species. 
Some  of  the  names  listed  in  Table  1  cover  a  number  of 
species. 

Consumption  of  Box  Lumber  by  States — The  total 
amount  of  wood  consumed  in  each  State  by  box  manufac- 
turers and  the  total  lumber  cut  of  each  State  are  given  in 
Table  2.  This  is  shown  graphically  in  figure  1,  in  which 
the  size  of  the  squares  in  each  State  represents  the  relative 
total  consumption  of  wood  for  boxes,  crates,  and  fruit  and 
vegetable  packages.  The  statistics  used  in  Table  2  come 
from  the  same  source  as  those  in  Table  1.  Table  3  shows 
the  principal  woods  used  in  the  important  box  manufactur- 
ing States.  This  table  is  limited  to  include  only  the  24  most 
important  box  manufacturing  States  and  the  19  most  im- 
portant species;  but  the  24  States  are  located  in  all  parts  of 
the  country,  so  that  the  table  shows  what  woods  are  most 
used  in  every  part  of  the  United  States. 

Distribution  of  Box  Lumber — Some  of  the  largest  box 
manufacturing  States  produce  but  little  of  the  lumber  so 
used.  In  this  class  are  Illinois,  Pennsylvania,  and  New 
York.  Other  States  which  are  of  medium  rank  in  the  box 
industry,  but  produce  very  little  box  lumber,  are  New  Jersey, 
Maryland,  Ohio,  and  Indiana. 

From  the  region  south  of  the  Ohio  and  Potomac  Rivers 
box  lumber  moves  northward  to  consuming  points  in  two 
general  currents,  separated  by  the  Appalachian  Mountains ; 
that  is,  North  Carolina  pine  from  Virginia  and  the  Caro- 
linas  goes  northward  east  of  the  Allegheny  Mountains,  while 
from  the  Central  and  Gulf  States  yellow  pine,  red  gum,  etc., 


WOODEN  BOX   AND    CRATE   CONSTRUCTION 


TABLE  2.    Box  LUMBER  CONSUMPTION  AND  TOTAL  LUMBER  PRODUCTION 

BY  STATES 


State 

Quantity  used 
annually  for  boxes 
(1912) 

Total  lumber 
production 
(1918) 

Feet 
board  measure 

Feet 
board  measure 

Virginia  
New  York 

433,028,997 
390,057,650 

855,000,000 
335,000,000 

Illinois  
Massachusetts  
California 

389,199,000 
353,405,350 
309,406,285 

42,000,000 
175,000,000 
1,277,084,0001 

Pennsylvania 

276,587,094 

530,000,000 

Michigan  
New  Hampshire  
Ohio  

232,111,486 
200,209,596 
153,417,273 

940,000,000 
350,000,000 
235,000,000 

Maryland  
Wisconsin  
Kentucky  
Missouri  
Arkansas  
Maine 

144,309,000 
119,267,000 
112,424,500 
111,765,699 
110,822,000 
108  889,400 

71,000,000 
1,275,000,000 
340,000,000 
273,000,000 
1,470,000,000 
650,000,000 

New  Jersey  .  . 

102  605,205 

19,500,000 

\Vashington2 

96  448,500 

4,603,123,000 

Indiana  
Oregon2  
Tennessee  
Minnesota  ,  
North  Carolina  
Louisiana 

85,267,160 
78,939,000 
77,979,510 
77,854,600 
76,525,000 
56  004  500 

250,000,000 
2,710,250,000 
630,000,000 
1,005,000,000 
1,240,000,000 
3,450,000,000 

Florida  
Vermont  
Mississippi  
Texas  
Iowa                           .    .    .    .  '  

53,469,000 
48,871,060 
39,295,093 
35,762,125 
31,340,476 

950,000,000 
160,000,000 
1,935,000,000 
1,350,000,000 
14,200,000 

Kansas  
Arizona  and  New  Mexico  
Delaware  
Connecticut  
Georgia  
West  Virginia  
Alabama  
Rhode  Island  
South  Carolina  
Idaho  
Nebraska  
Montana  
Colorado  
Oklahoma  
Nevada  and  Utah  
District  of  Columbia  
North  and  South  Dakota  
Wyoming  

28,544,500 
28,035,000 
27,624,175 
24,411,090 
24,373,409 
23,837,000 
22,442,000 
15,951,200 
13,960,000 
10,245,000 
6,861,000 
5,249,927 
4,734,000 
4,389,000 
1,517,000 
518,655 
18,667 
none 

8,401,000 
172,576,000 
6,000,000 
64,000,000 
515,000,000 
720,000,000 
'1,270,000,000 
13,100,000 
545,000,000 
802,529,000 
none 
340,000,000 
56,882,000 
195,000,000 
9,815,000' 
none 
29,533,000* 
7,501,000 

Total  

4,547,973,180 

31,890,494,000 

California    and   Nevada. 

21914    statistics    on    box    lumber    consumption    are    available:      Washington,    106, 
307,980  feet  board  measure  ;  Oregon,  72,299,344  feet  board  measure. 
3Utah    only.     4South    Dakota    only. 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON 


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Maple 


Yellow  poplar 


Hemlock 


Cottonwood 


Western 
Yellow  pine 


Spruce 


Red  gum 


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8  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

move  approximately  straight  northward.  Material  from  the 
Lake  States,  •principally  Minnesota,  Wisconsin,  and  northern 
Michigan,  moves  to  northern  Illinois  and  Indiana.  Canadian 
white  pine  goes  into  Michigan,  northern  Ohio,  and  western 
New  York.  New  England  is  to  a  considerable  extent  self- 
supporting  as  regards  box  lumber,  although  considerable 
North  Carolina  pine  gets  into  Connecticut  and  Rhode  Island 
and  some  Canadian  white  pine  goes  into  northern  New  Eng- 
land. The  Western  Pacific  States  are  not  only  self  support- 
ing but  at  times  supply  considerable  material  to  the  territory 
east  of  them.  Some  box  material  is  shipped  from  Arizona 
and  New  Mexico,  principally  to  the  middle  west.  Mexican 
pine  is  used  by  some  of  the  box  factories  on  the  Mexican 
border. 

As  the  outcome  of  conditions  resulting  from  the  war, 
many  of  the  different  species  may  now  be  found  in  markets 
far  removed  from  their  regions  of  growth,  e.  g.,  white  pine 
from  New  England  is  manufactured  into  boxes  in  Texas 
and  spruce  from  Oregon  and  Washington  in  Massachusetts. 

COMMERCIAL    GRADES   AND    SIZES    OF   LUMBER    AVAIL- 
ABLE FOR  BOX  CONSTRUCTION 

STANDARD  DEFECTS  AND  BLEMISHES  IN  LUMBER 

Commercial  lumber  grades  are  based  on  the  number,  size, 
and  position  of  the  defects  and  blemishes  the  lumber  contains, 
and,  to  a  certain  extent,  on  the  size  of  the  pieces. 

Defect  —  A  defect  is  any  irregularity  occurring  in  or  on 
wood  that  may  lower  some  of  its  strength  values. 

Blemish  —  A  blemish  is  anything  not  classified  as  a  de- 
fect which  mars  the  appearance  of  the  wood. 

The  following  arc  the  principal  recognized  defects  and 
blemishes  in  lumber  which  may  lower  its  grade1.  (See  also 
Plate  I.) 

1.  Knots  —  Knots  are  irregularities  of  growth  caused  by 
the  junction  of  a  branch  with  the  body  of  a  tree.  These  are 
further  classified  as  to  size,  shape,  and  quality. 

A  pin  knot  is  less  than  y2  inch  in  diameter. 

A  standard  knot  is  from  */2  to  1       inches  in  diameter. 


lrThe  definitions  of  defects  as  here  given  are  not  universally  accepted.  For 
example,  a  standard  knot,  according  to  the  West  Coast  Lumbermen's  Association, 
is  from  %  to  1%  inches  in  diameter;  under  the  rules  of  the  Southern  Cypress  Manu- 
facturers' Association  a  standard  knot  is  from  %  to  1%  inches  in  diameter  ;  and 
according  to  the  two  hardwood  associations  a  knot  1*4  inches  in  diameter  is  con- 
sidered a  standard  defect.  At  the  present  time,  standard  definitions  of  terms  re- 
lating to  defects  and  blemishes  are  being  revised  by  the  National  Association  of 
Lumber  Manufacturers. 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON        9 

A  large  knot  is  over  \l/2  inches  in  diameter. 

A  round  knot  is  circular  or  oval  in  form. 

A  spike  knot  is  cut  through  lengthwise,  and,  therefore, 

can  occur  on  quarter-sawed  surfaces  only. 
A  sound  knot  is  as  hard  as  the  wood  it  is  in,  and  is  so 

fixed  by  growth  or  position  that  it  will  retain  its  place 

in  the  piece. 
An  encased  knot  is  not  firmly  connected  throughout  with 

the   surrounding   wood.      If   intergrown   partially   with 

the  surrounding  wood  or  so  held  by  shape  or  position 

that  it  will  retain  its  place  in  the  piece,  it  is  considered 

a  sound  knot. 
A  water-tight  knot  is    completely    intergrown    with    the 

surrounding  wood  on  one  face,  and  is  sound  on  that 

face. 

A  loose  knot  is  not  firmly  held  in  position ;  it  may  drop  out. 
A  pith  knot  is  a  sound  knot  with  a  hole  not  over  %  inch 

in  diameter  at  the  center. 
A  rotten  knot  is  not  so  hard  as  the  wood  it  is  in. 

2.  Shake — Shake  is  a  partial  or  entire  separation  of  the 
wood  between  annual  rings. 

3.  Checks — Checks  are  splits  which  run  radially  across 
the   rings.     They   are   usually   due   to   unequal   shrinkage   in 
seasoning. 

4.  Splits — Splits  are  due  to  rough  handling  or  internal 
stresses  and  are  easily  confused  with  checks  and  shakes. 

5.  Pitch  Pockets — Pitch   pockets  are  lens-shaped  open- 
ings between  the  annual  rings  of  some  conifers  and  contain 
more  or  less  pitch  or  bark. 

6.  Pitch  Streaks — Pitch  streaks  are  conspicuous  accumu- 
lations of  pitch  in  the  wood  cells. 

7.  Wane — Wane  is  bark  on  the  edge  of  a  piece  or  the 
absence  of  the  square  edge. 

8.  Rot  and  Dote — Rot  and  dote  refer  to  different  stages 
of  decay  due  to  wood-destroying  fungi.     Either  is  permissible 
to  a  certain  extent  in  the  lower  grades  of  lumber. 

9.  Stain — Stain  (as  blue  stain,  brown  stain,  water  stain, 
and  others   not   due   to   decay)    usually   affects  only   the   ap- 
pearance of  lumber  and  is  not  considered  a  defect  in  the  lower 
grades. 

10.  Pith — Pith   is  the  small   soft  core   at  the   structural 
center   of   a   log.      It   is   often    surrounded   by    small    checks, 


10  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

shakes,  numerous  pin  knots,  etc.     In  some  woods  it  is  large 
enough  to  be  objectionable  on  the  face  of  lumber. 

11.  Worm    Holes — Worm    holes    are    very    common    in 
some  woods  and  may  render  them  unfit  for  high-grade  work. 
They  may  be  small,  in  which  case  they  are  known  as  pin- 
worm  holes,  or  if  in  groups,  shot-worm  holes ;  or  they  may 
be  large,  in  which  case  they  are  known  as  grub-worm  holes. 

12.  Bird  Pecks  and   Gum  Spots — Bird   pecks  and   gum 
spots  appear  as  brown  or  black  discolorations.     Sometimes 
an  open   cavity  is  formed,  which  in  the   case  of  gum   spots 
may  contain  a  gum-like  substance. 

13.  Rafting  Pin  Holes — Rafting  pin  holes  may  be  bored 
for  rafting  pins  or  holes  made  by  driving  rafting  pins  into 
the  wood. 

14.  Warping — Warping     includes     both     twisting     and 
cupping  and   is   due   mostly   to   improper   piling  and   drying 
methods  and  may  cause  clear  lumber  to  be  put  in  a  low  grade. 

15.  Crook — A  crook  is  the  curving  of  a  piece  edgewise 
in  the  longitudinal  direction. 

16.  Bow — A  bow  is  the  deviation  of  a  piece  flatwise. 

17.  Twisting — Twisting   is    the    turning   or    winding   of 
the  edges  of  a  piece  so  that  the  four  corners  of  a  face  are  no 
longer  in  the  same  plane. 

18.  Cupping — Cupping  is  the  curving  of  a  piece  across 
the  grain  or  width  of  the  piece. 

19.  Poor  Manufacture — Poor  manufacture,   as   irregular 
width   or   thickness   or   chipped   or  torn   grain,   is   cause   for 
putting  lumber  in  a  lower  grade. 

GRADING  ACCORDING  TO  SIZE  OF  LUMBER 

Standard  Sizes  of  Lumber — The  sizes  of  lumber  avail- 
able to  the  box  manufacturer  are,  in  general,  the  same  as  are 
made  for  the  general  lumber  trade.  The  thicknesses  used  are 
normally  in  the  rough,  4/4,  5/4,  6/4,  7/4,  and  8/4  inches.  These 
thicknesses  are  resawed  in  the  box  factory  to  produce  1/4, 
5/16,  3/8,  7/16,  1/2,  9/16,  5/8,  11/16/3/4,  and  13/16- 
inch  material  surfaced  on  one  side  or  scantily  surfaced  on 
two  sides.  The  widths  range  from  about  3  or  4  inches  up 
to  about  12  inches,  or  sometimes  up  to  16  inches.  In  some 
woods,  stock  widths  only  are  manufactured,  that  is,  even-inch 
widths  (4,  6,  10,  and  12,  etc.,  inches)  ;  in  other  woods,  both 
stock  and  random  sizes  (odd  inch  and  fractional  inch  widths) 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      11 

are  made ;  in  hardwoods,  random  widths  only  are  standard,  but 
they  are  measured  to  the  nearest  whole  inch.  Lengths  of  box 
lumber  generally  range  from  1  to  20  feet.  Regular  grades  are 
often  cut  from  6  or  8  feet  up  to  16  or  20  feet ;  while  a  special 
grade,  usually  known  as  short  box,  includes  the  shorter 
lengths. 

Much  of  the  lumber  cut  in  the  New  England  States  is 
not  edged  at  the  mill  but  is  put  on  the  market  in  the  form 
of  tapering  boards  with  waney  edges.  This  is  known  as 
"round-edged"  lumber  and  consists  mostly  of  second-growth 
white  pine,  spruce,  hemlock,  and  fir.  About  10  per  cent  more 
box  lumber  can  be  cut  from  New  England  timber  if  it  is  not 
edged  until  after  it  is  cut  to  lengths  and  if  it  is  not  edged  to 
standard  widths.  On  account  of  the  difficulty  of  satisfactorily 
grading  round-edged  lumber,  it  is  not  graded,  as  a  rule,  but 
is  sold  as  long  run. 

Grades  Suitable  for  Boxes  and  Crates — Grading  rules 
for  a  certain  species  or  group  of  woods  are  prepared  by  the 
lumbermen's  associations  particularly  interested  in  that  kind 
of  lumber.  At  the  present  time  there  are  a  number  of  lum- 
ber associations  which  have  standard  grading  rules.  Some 
woods  are  graded  by  more  than  one  association  under  rules 
which  are  not  similar,  a  condition  which  causes  more  or  less 
confusion  in  preparing  lumber.  Neither  are  the  names,  quali- 
ties, or  sizes  of  similar  grades  of  the  different  associations 
always  alike. 

The  upper  grades,  which  contain  fewest  defects  and  a 
very  limited  per  cent  of  narrow  widths  and  short  lengths,  are 
seldom  used  in  the  manufacture  of  shipping  containers.  The 
low  grades,  which  contain  more  or  less  knots  and  other  de- 
fects, furnish  the  material  commonly  used. 

The  problem  of  the  manufacturer  is  to  cut  out  the  de- 
fects not  permissible  in  the  kind  of  boxes  he  is  making  and 
to  do  this  with  as  little  waste  as  possible  and  with  the  least 
expenditure  of  power  and  labor.  In  general,  the  waste  of 
lumber  in  making  boxes  is  from  15  to  20  per  cent.  Insistence 
upon  boxes  finished  without  knots  would  result  in  a  much 
larger  waste  or  in  the  use  of  a  finishing  grade.  Because  of 
the  cost  of  lumber  and  labor,  box  specifications  should  permit 
the  use  of  low  grades  and  cause  as  little  waste  in  working 
up  the  lumber  as  is  consistent  with  the  box  requirements. 


12 


WOODEN   BOX   AND    CRATE   CONSTRUCTION 


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14  WOODEN  BOX   AND    CRATE   CONSTRUCTION 

IMPORTANT   PHYSICAL  PROPERTIES   OF  WOOD   WHICH 
INFLUENCE   ITS   USE   IN   BOX   CONSTRUCTION 

WEIGHT 

Importance — The  weight  of  the  wood  used  for  packing 
boxes  and  crates  is  very  important.  It  influences  the  cost  of 
both  handling  and  transportation.  The  strength,  shrinking, 
and  warping  of  lumber,  and  the  ease  with  which  it  splits  in 
nailing  increase,  as  a  rule,  with  the  dry  weight.  Where 
strength  is  an  important  factor,  light  pieces,  no  matter  what 
the  species  may  be,  should  not  be  used.  Thinner  pieces  may 
be  used  of  the  heavier  woods  than  of  the  lighter  woods, 
without  reducing  the  strength.  The  denser  woods  hold  nails 
better  and  are  desirable  on  this  account.  On  the  other  hand, 
the  lighter  woods  give  less  trouble  in  seasoning  and  manu- 
facture. 

How  the  Weight  of  Lumber  is  Expressed — In  commer- 
cial practice  the  weight  of  lumber  is  usually  expressed  in 
pounds  per  thousand  board  feet  when  "shipping-dry."  This 
ranges  from  about  2,100  pounds  for  very  light  woods  to  over 
4,000  pounds  for  very  heavy  woods.  A  more  definite  way  of 
expressing  the  weight  of  wood  is  in  pounds  per  cubic  foot 
or  per  square  foot  of  specified  thickness  at  any  given  mois- 
ture content  or  degree  of  seasoning,  as  green,  thoroughly  air 
dry,  kiln  dry,  or  oven  dry.  For  the  convenience  of  box  de- 
signers and  manufacturers  the  approximate  weights  for  dif- 
ferent thicknesses  of  box  lumber  and  veneer  are  given  in 
Table  4. 

The  weight  is  often  expressed  in  terms  of  specific  grav- 
ity, which  means  the  ratio  of  the  weight  of  an  object  to  the 
weight  of  an  equal  volume  of  water.1  To  determine  the 
specific  gravity  of  wood,  it  is  customary  to  use  the  oven-dry 
weight  and  the  volume  measured  while  the  wood  is  in  the 
same  condition  or  when  green  or  partly  dry.  It  should  always 
be  stated  under  what  moisture  condition  the  weight  and 
volume  were  measured.  Table  4  gives  the  specific  gravity 
of  box  woods. 

FACTORS  WHICH  INFLUENCE  THE  WEIGHT  OF  LUMBER 

1.  Species — A  great  variation  is  found  in  the  weight  of 
the  various  commercial  species,  as  can  be  seen  from  Table  4. 


'A    cubic    foot   of    water    weighs    approximately    62.5    pounds. 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      15 

2.  Density,    or   Amount   of   Wood    Substance — Even  in 
the   same   species   there   is   considerable    variation    in   weight 
due  to  differences  in  density  (the  figures  given  in  Table  4  are 
only  average,  or  approximate).     Species  growing  in  the  wet 
swamps    of    the    South    show    the    greatest    variation.      The 
swelled   butt   logs   of   trees    growing    in     places     where     the 
ground  is  covered  with  water  a  large  part  of  the  year  usually 
contain  very  light  wood.     Higher  up  in  the  tree  the  wood  is 
denser     and     heavier.      Very    light    pieces    of    cotton    gum 
(tupelo),  cypress,  and  ash  usually  come  from  such  localities. 
Ordinarily,  however,  butt  logs  produce  the  heaviest  wood. 

3.  Moisture  Content — The    moisture    in    kiln-dry    wood 
adds  only  about  5  or  10  per  cent  (occasionally  more)  to  the 
weight,  but  in  green  wood  the  water  contained  may  weigh 
more  than  the  wood  itself.     Thoroughly  air-dry  wood  usually 
contains  from  12  to  15  per  cent  moisture. 

4.  Resin   Content — In   yellow   pine,    Douglas   fir,   tama- 
rack, and  occasionally  in  spruce,  parts  of  the  tree  trunk  be- 
come infiltrated  with  resin  to  a  considerable  extent.     "Fatty 
pieces,"  as  such  resinous  pieces  are  called,  are  considerably 
heavier  than  normal  wood. 

MOISTURE  CONTENT 

Importance — A  knowledge  of  how  much  moisture  is  con- 
tained in  wood  when  manufactured  and  when  put  into  use  is 
exceedingly  important.  When  boxes  or  shocks  are  manu- 
factured under  certain  moisture  conditions  and  then  stored 
in  a  warehouse  or  shipped  to  a  drier  or  wetter  climate,  the 
moisture  content  will  accommodate  itself  to  the  varied  at- 
mospheric conditions.  This  affects  the  shrinking  or  swelling, 
warping,  checking,  weight,  strength,  and  nail-holding  power 
of  the  wood. 

How  Determined — To  determine  the  approximate  mois- 
ture content  of  a  stack  of  box  material : 

Select  one  representative  piece  from  every  100  or  500 
pieces.  In  the  case  of  lumber,  sections  l/2  inch  or  less  with 
the  grain  should  be  cut  two  or  more  feet  from  the  end  at 
a  place  free  from  knots,  rot,  or  other  abnormalities,  and 
where  sapwood  and  heartwood  are  in  representative  propor- 
tions. 

Immediately  after  cutting  these  sections,  pick  off  all  loose 
slivers  and  weigh  the  samples  to  an  accuracy  of  one-half  of 


16  WOODEN   BOX   AND  ^CRATE   CONSTRUCTION 

1  per  cent.  If  a  delicate  scale  is  not  available,  several  sec- 
tions may  be  taken  out  of  each  piece  to  insure  greater  ac- 
curacy. This  weight  we  will  call  the  original  weight. 

Dry  the  sections  in  an  oven  in  which  an  even  tempera- 
ture of  about  212°  F.  and  free  circulation  of  air  over  end 
grain  can  be  maintained,  until  they  no  longer  lose  in  weight. 
Sections  ^  inch  long  will  usually  dry  out  completely  over 
night.  If  a  drying  oven  is  not  available,  the  samples  will 
reach  within  1  or  2  per  cent  of  the  same  dryness  when  laid 
on  pipes  containing  live  steam. 

Weigh  the  dry  samples  to  an  accuracy  of  one-half  of 
1  per  cent  and  subtract  this  oven-dry  weight  from  the  orig- 
inal weight.  Divide  the  difference  by  the  oven-dry  weight 
and  multiply  by  100.  This  gives  the  per  cent  moisture 
based  on  the  oven-dry  weight. 

Thus,  if  the  original  weight  is  625.7  grams  and  the  oven- 
dry  weight  438.2  grams,  the  moisture  content  is : 
625.7—438.2=187.5  grams;  and 

187  5 

.       '    x  100=42.8  per  cent  moisture  content 

400 .  £ 

Variation — In  green  timber  the  moisture  content  ranges 
from  about  30  to  250  per  cent,  based  on  oven-dry  weight.  In 
so  called  air-dry  wood  it  may  range  from  5  or  8  per  cent,  as 
in  small  pieces,  to  over  30  per  cent,  as  in  limber  dried  to  re- 
duce its  shipping  weight.  Kiln-dry  wood  is  also  highly  vari- 
able in  moisture  content,  depending  on  the  purpose  for  which 
it  is  dried  and  the  care  with  which  the  drying  is  carried  on. 
If  the  object  of  the  drying  is  to  reduce  quickly  the  shipping- 
weight,  the  lumber  may  be  no  drier  or  not  even  so  dry  as  it 
would  become  from  prolonged  air  drying.  On  the  other  hand, 
lumber  may  become  too  dry  in  a  kiln  and  give  trouble  during 
and  after  manufacture. 

How  the  Moisture  is  Contained  in  Wood — The  troubles 
from  shrinking,  swelling,  warping,  and  cupping  of  lumber 
when  put  into  use  arise  from  the  manner  in  which  the  mois- 
ture is  held  in  the  wood.  It  is  held  principally  in  tw7o  ways, 
(1)  rilling  the  cell  cavities  and  (2)  absorbed  in  the  cell  walls. 
When  wood  dries,  the  moisture  first  leaves  the  cell  cavities, 
and  after  they  are  empty  it  begins  to  leave  the  cell  walls. 
The  condition  in  which  the  cell  cavities  are  empty  but  the 
cell  walls  still  fully  saturated  is  known  as  the  "fiber-satura- 
tion point."  As  a  rule  wood  does  not  shrink  in  drying  or  lose 
in  strength  until  the  moisture  content  falls  below  the  fiber- 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      17 

saturation  point.  This  moisture  content  ranges  from  20  to  35 
per  cent.  The  moisture  content  of  seasoned  lumber  does  not 
remain  constant  but  varies  with  the  humidity  of  the  surround- 
ing atmosphere.  This  is  due  to  the  cell  walls  giving  off  or 
absorbing  moisture.  •  (The  curve  in  figure  2  shows  the  mois- 


Curves  shoi 
when   at  equi 
of    various    hi 
peratures. 
Curve  A,  be 
(Data  by  M. 
Curve  B,  in 
Curve  C,  ba 
(Data  by  H.   ] 
Broken  line 

ving  the  moisture  content   of  wood 
ibrium  with   atmospheric  conditions 
imidities    and    three    different    tem- 

ised  on  the  average  of  five  species. 
E.   Dunlap.) 
terpolated. 
sed  on  the  average  of  nine  species. 
E.   McKenzie.) 
5  indicate  absence  of  exact  data. 

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FIG.  2 — Relation  of  moisture  content  of  wood  to  relative  humidity. 


ture  content  at  which  wood  will  ultimately  arrive  under  a 
given  humidity  and  various  temperatures.  It  is  based  on  only 
a  limited  number  of  woods  but  is  believed  to  be  representa- 
tive for  most  species.)  This  relation  of  the  moisture  content 
of  wood  to  the  relative  humidity  is  of  great  significance  in 
the  manufacture  and  use  of  wooden  articles. 

Proper  Moisture  Content  of  Box  Lumber — The  moisture 
content  of  wood  for  any  purpose  should  be,  at  the  time  of 
manufacture,  approximately  what  it  will  be  when  the  wood  is 
in  use.  For  boxes  and  crates  from  12  to  18  per  cent  is  con- 
sidered a  safe  approximation. 

If  the  lumber  used  has  too  high  a  moisture  content  vari- 
ous weaknesses  develop  later  (see  page  47)  ;  the  box  will  be 
heavier  than  necessary;  if  it  is  made  for  a  standard-sized  ar- 
ticle, it  will  not  fit  the  contents  unless  allowance  is  made  for 
shrinking;  and  if  it  is  not  assembled  immediately,  the  dif- 
ferent parts  may  not  fit  together  properly. 


18 


WOODEN  BOX   AND    CRATE   CONSTRUCTION 


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FIG.  3 — Relation  between  the  volumetric  shrinkage  and  specific  gravity  of  various 
American  woods.   See  opposite  page  for  list  of  species  and  reference  numbers. 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      19 


HARDWOODS 

Species  Locality  Bef.  No. 

Alder,     red Wash..     30 

Ash,  biltmore    Tenn 91 

black    Mich 60 

black     Wis 70 

blue    Ky 99 

green   La 93 

green   Mo 100 

pumpkin    Mo 79 

white    Ark 106 

white    N.    Y 128 

white    W.   Va 83 

Aspen     Wis 23 

largetooth    Wis 20 

Basswood    Pa 12 

Wis 5 

Beech     Ind 110 

Pa 98 

Birch,  paper     '....Wis 73 

sweet    Pa 129 

yellow  Pa-    107 

yellow  Wis 103 

Buckeye,    yellow Tenn 9 

Buckthorn,    cascara    Ore 84a 

Butternut    ................ ..Tarn.    ;••;••;;  g 

Chinquapin', '  Western  ".'.'.'.'.'.'.  Ore.'   46b 

Cherry,    black     Pa 72 

Cherry,    wild    red Tenn 24 

Chestnut     ..-. Md 46 

Tenn 40 

Cottonwood,     black     Wash 6 

Cucumber    tree Tenn 59 

Dogwood     (flowering) ...Tenn 151 

(Western)     Ore.    12oa 

Elder,    pale    Ore 69a 

Elm,    cork    Wis.,    Marathon    Co... 126 

Wis.,  Busk  Co.  120 

Elm,    slippery    Ind 102 

slippery Wis 74 

white    Pa 55 

AVhite    Wis 53 

Greenheart    165 

Gum,  black   Tenn 68 

blue    (eucalyptus)    Cal 147 

cotton    La 76 

red    Mo 54 

Haw.    pear  ' .' .' .' .' '. '. '. '. .' .' '. '. '. '. '. '.  Wis.'    .'-.' .' .' .' '.'.'.'.  146 

Hickory,  big    shellback    Miss 135 

big    shellback    Ohio  154 

Hickory,  bitternut     °hio     139 

mockernut    Ml«s 144 

mockernut    Pa 159 

mockernut    W.   Va 155 

nutmeg    Miss 112 

pignut    Miss 148 

pignut    Ohio     157 

pignut    Pa 160 

Pignut    W.   Va 161 

shagbark     Miss 140 

shagbark     Ohio     152 

shagbark     Pa 143 

shagbark     W.   Va 153 

water   Miss 141 

Holly,  American  Tenn 87 

Hornbeam   Tenn 149 

Laurel,     mountain     'L0nn ^15 

Locust,  black   Tenn 158 

honey     .  ... Ind 162 

Madrona   Cal 101 

Ore 128a 

Magnolia,  .!*• ,  66 

Maple,  Oregon   Wash 58 

red     .  ...Pa 69 

red    ..  ...Wis 92 

silver    Wis 56 

sugar    Ind 104 

sugar    Pa 108 

sugar    Wis 124 

Oak,  burr    Wis 125 

California   black    Oal 80 

canyon   live   .' .  Cal 163 

chestnut    Tenn.    121 

cow   La ..133 

laurel     La 116 

post    Ark 130 

post    La 137 

red   jLrk 119 


Species  Locality  Bef 

Oak.  red Ind 

red    La.    

red    Tenn 

Highland  Spanish   La.    

Lowland  Spanish  La 

swamp    white    Ind 

tanbark    Cal 

water    La 

white   / Ark 

white   Ind. 


white   La.,    Bichland    Parish... 

white   La.,   Winn  Parish 

willoAV    La 

yellow     Ark 

yellow     Wis 

Osage    orange     Ind     . 

Poplar,  yellow   (tulip-tree) .  ..Tenn.    . 

Bhododenron,    great    Tenn. 

Sassafras    Tenn!    . 

Servioeberry   Tenn.    . 

Silverbell-tree   Tenn.    . 

Sourwood    Tenn.    . 

Sumac,    staghorn    Wis.    . . 

Sycamore    . . .  i Ind.    . . 

Tenn.   . 

Umbrella,  Fraser Tenn.   . 

Willow,    black    Wis.    .. 

Willow,     Western    black Ore.    .. 

Witch   hazel    Tenn.    . 

CONIFERS 


No. 

118 

117 
97    ' 
94 

142 

150 

115 

111 

132 

138 

136 

131 
.109 
.122 
.105 
.164 
.  35 
.  85 
.  51 
.156 
.  49 
.  89 
.  61 
.  63 
.  65 
.  45 
.  11 
.  43a 
.114 


Species 

Locality   Bef.  No. 

Cedar,  incense    

Cal  26 

Western    red 

Mont  2 

Western    red 

Wash  10 

white    

Wis,    1 

rvpress.   bald   

La  62 

Fir,  Alpine    

Colo  4 

amabilis  

Ore  39 

amabilis   

Wash  18 

balsam    

Wis  14 

Douglas   

Cal  45a 

Douglas   

Ore  67a 

Douglas   

...Wash,    and   Ore  67 

Douglas   

...Wash.,  Lewis  Co  75 

Douglas   

.  .  .  Wash.,  Chehalis  Co.  .  46a 

Douglas   

Wyo  48 

grand    

Mont  36 

noble    

Ore  16 

white    

Cal  17 

Hemlock,   black    ... 

Mont  47 

Eastern    . 

Tenn  52 

Eastern   . 

Wis  15 

Western   . 

Wash  50 

Laroh,  Western     .  .  . 

Mont  84 

Western     .  .  . 

Wash  64 

Pine,  Cuban     

..  Fla  127 

jack    

...Wis  43 

Jeffrey    

...Cal  33 

loblolly    

...Fla  88 

lodgepole    .  .  . 

Colo  31 

lodgepole    .  .  . 
lodgepole    .  .  . 

...Mont.,   Gallatin  Co..  35a 
...Mont.,    Granite   Co..  41a 

lodgepole    .  .  . 

...Mont.,  Jefferson  Co..   40a 

lodgepole    .  .  . 
longleaf  
longleaf   
longleaf   
longleaf  

Wyo  34 
Fla  123 
.La.,  Tangipahoa  Parish  96 
.La.,    Lake    Charles  113 
Miss  95 

Norway    

Wis  57 

pitch  

Tenn  71 

pond   

Fla  86 

shortleaf   

Ark  77 

sugar    

Cal  22 

Table   Mounta 

im    Tenn,    82 

Western  white 

Mont  42 

Western  yellow Aril 19 

Western     Cal 37 

Western     Colo 41 

Western     Mont 32 

white    Wis 25 

Bedwood     Cal.,    Albion..  28 

Cal.,    Korbel..  13 

Spruce,  Engelmann    .Colo.,    San   Micuel    Co.  3 

Engelmann    .Colo.,    Grand   Co 8 

red    N.    H 44 

red    Tenn 29 

white    N.    H 7 

white   Wis.    38 

Tamarack   Wis 81 


Yew,  Western 


..Wa«h 134 


20 


WOODEN  BOX  AND   CRATE   CONSTRUCTION 


If   the   lumber   is   too    dry,    it   splits   more   easily   during 

I  manufacture  and  in  nailing,  and  is  slightly  more  difficult  to 

work ;  and,  although  the  strength,  of  the  wood  is  greater,  the 

assembled  box  is  considerably  weaker  than  one  of  the  proper 

moisture   content.1     Furthermore,  the  wood  will   swell  later, 


A  B 

FIG.  A — Cupping  of  lumber 

A.  Cupping  of  the  two  halves  of  a  resawed  board. 

B.  Cupping  of  plain-sawed  lumber  while  seasoning. 

bulging  and  warping,  which  will  result  in  extra  strain  on  the 
nails,  sometimes  bending  or  withdrawing  them.  If  the  shooks 
are  stored  in  a  knock-down  condition  they  may  not  fit  closely 
together  when  later  assembled. 

Dry  wood  is  stronger  in  most  respects  than  green  wood 
of  the  same  quality.  The  increase  begins  as  soon  as  the  wood 
dries  to  below  the  fiber-saturation  point.  No  allowance,  how- 
ever, for  increase  in  strength  above  that  of  green  material 
should  be  made  for  large  dimension  stock  used  for  skids  for 
crates,  etc.,  because  very  often  these  are  not  below  the  fiber- 
saturation  point  in  the  interior  and  seasoning  checks  may 
develop  which  counteract  any  increased  strength  of  the  fibers 
due  to  seasoning. 

^his  is  discussed  in  greater  detail  in  Chapter  II,  page  47, 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      21 


18000 

L 

16000 

\ 

1*5000 

\ 

Variations    Due  to  Changes 
in    Moisture    Content 

14000 

V 

Moisture    strength 
Percent  atMax.Load 

Modulus 
of 
Rupture 

Modulus 
of 
Elasticity 

\ 

Green*       1.00 

1.00 

1.00 

30          1.04 

1.03 

1.01 

°, 

%V- 

5 

^"*  ^V 

25          1.25 

1.19 

1.10 

20          1.48 

1.36 

1.17 

i  1  nnn 

15          1.77 

1.55 

1.25 

10          2.19 

1.78 

1.31 

Z 

c>  i  nonn 

\ 

*' 

5          2.76 

2.08 

1.37 

0          3.45 

2.40 

1.42 

CO 

a: 
£     9000 

CO 
Q 

i 

^ 

•\ 

^3: 

%  and 

above 

0 

, 

"^    \ 

1 

\ 

e 

\ 

J 

J\ 

7000 

^ 

5000 

% 

vS^ 

\ 

>'XV 

% 

8 

2000 
1000 

'SS 

3  : 

US  of  £ 

''astic/t 

»  ( 

y/nOn 

eThou 

2     x 

sand  L 

B  Unit 

5  2"x  2 

"x  30  "Beams 

0 

MOISTURE   PERCENTAGE   BASED  ON    DRY  WEIGHT 


FIG.  5 — Effect  of  moisture  upon  the  strength  of  small  clear  specimens  of 

western  hemlock. 


22  WOODEN  BOX  AND   CRATE   CONSTRUCTION 

The  various  strength  properties  of  wood  do  not  increase 
in  the  same  proportion  as  wood  seasons.  This  is  shown  for 
western  hemlock  in  figure  5.  In  the  case  of  shear  along  the 
grain,  wood  very  often  fails  to  show  large  increase  in  strength 
as  it  dries,  probably  because  of  the  checks  which  form  in 
shrinking.  The  shock  resisting  ability  shows  no  appreciable 
increase  in  most  woods  and  decreases  slightly  in  many  species 
while  seasoning. 

There  is  more  or  less  prejudice  against  kiln-dried  lumber 
for  use  where  strength  is  essential.  There  is  no  doubt  that  a 
large  amount  of  lumber  is  damaged  by  improper  methods  of 
kiln  drying.  However,  properly  kiln-dried  material  is  just  as 
strong  as  similar  lumber  air-dried  to  the  same  moisture  con- 
tent, and  may  be  even  stronger. 

SHRINKING  AND  SWELLING  OF  WOOD 

Extent — When  green  or  soaked  wood  dries  it  does  not 
shrink  until  it  gets  down  to  about  25  to  30  per  cent  moisture 
(fiber-saturation  point)  and  from  there  on  it  shrinks  until  the 
oven-dry  condition  is  reached.  Conversely,  when  dry  wood 
absorbs  moisture  it  swells  until  the  fiber-saturation  point  is 
reached  and  beyond  that  there  is  no  more  change  in-  dimen- 
sions, although  absorption  may  continue,  increasing  the 
weight.  Therefore,  about  half  of  the  total  -possible  shrinkage 
has  taken  place  when  wood  is  seasoned  down  to  12  or  15  per 
cent  moisture,  which  corresponds  to  the  thoroughly  air-dry 
condition  (see  figure  6).  Lumber  which  is  only  partly  sea- 
soned or  which  is  "shipping-dry"  when  received  in  the  fac- 
tory, may  not  have  shrunk  appreciably,  and  considerable 
shrinkage  may  take  place  during  and  after  manufacture. 

The  -total  shrinkage  from  the  green  to  the  oven-dry  con- 
dition varies  greatly  for  the  different  species  of  woods,  but  in 
general  it  increases  with  the  weight  of  the  wood.  Figure  3 
shows  the  relation  of  shrinkage  in  volume  to  specific  gravity. 

The  shrinkage  along  the  grain  is  so  slight  as  to  be  neg- 
ligible for  most  purposes.  Across  the  grain,  however,  it  is 
considerable ;  and  it  is  decidedly  less  radial  than  tangential 
in  the  same  piece  of  wood.  This  is  shown  in  Table  5. 

Occasionally,  what  appears  to  be  abnormal  shrinkage 
takes  place  in  drying  certain  kinds  of  lumber.  The  surfaces 
of  such  lumber  have  a  caved-in  or  corrugated  appearance 
when  dried.  (See  figure  7.)  Shrinkage  in  some  species  is 
more  likely  to  occur  when  the  wood  is  kiln-dried  from  the 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTOR      23 


saw  at  high  temperature.     In  such  cases,  some  of  the  cells  of 
the  wood  collapse  as  the  water  leaves  them.     This  does  not 

TABLE  5.     PER  CENT  OF  SHRINKAGE1  ACROSS  THE  GRAIN 


Frorfi  green  or  over 
30  per  cent  moisture 
to  the  oven-dry 
condition. 

From  green  or  over 
30  per  cent  moisture 
to   the    air-dry    con- 
dition —  12     to      15 
per  cent. 

Very  light 
woods 

Very  heavy 
woods 

Very  light 
woods 

Very  heavy 
woods 

Radial,  i.  e.,  across  the  rings 
Tangential,   i.   e.,   along  the 
rings  

2.6 

4.7 

6.3 
11.2 

1.3 
2.3 

3.1 
5.6 

occur  in  the  sap  wood  or  at  the  ends  or  edges  of  lumber 
where  air  can  readily  enter  the  wood  and  prevent  collapse  of 
the  cells. 


FIG.  6 — End  of  honeycombed  oak  plank. 

How  TROUBLES  FROM  SHRINKING  AND  SWELLING  MAY  BE 
REDUCED  TO  A  MINIMUM  IN  BOXES 

There  is  practically  no  method  of  treatment  by  means  of 
which  the  shrinking  and  swelling  of  wood,  when  exposed  to 
varying  atmospheric  conditions,  can  be  entirely  overcome ; 
but  if  the  following  precautions  are  observed  so  far  as  pos- 
sible in  the  selection  and  treatment  of  wood,  trouble  from 
these  sources  will  be  reduced  to  a  minimum. 

1.  Select  light  woods  if  other  requirements  permit. 

2.  Be   sure   the   wood   is   dried   to   the   proper  moisture 
content. 

3.  Use  quarter-sawed  lumber — this  is  practical  only  for 
special  boxes. 


Shrinkage  is  here  expressed  in  per  cent  of  green  dimension. 


24  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


FIG.  7 — Collapse  in  1-inch  boards. 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      25 

4.  Use  plywood,  that  is,  thin  sheets  of  veneer  glued  to- 
gether with  the  grain  crossed. 

5.  Cover  the  wood  with  oil,  paint,  or  other  protective 
coating. 

6.  Avoid  as  far  as  possible  storage  or  use  of  boxes  under 
widely  varying  atmospheric  conditions. 

Checking — Checking  in  wood  is  due  to  stresses  set  up  on 
account  of  uneven  shrinkage.  End  checking  is  very  common 
and  often  can  not  be  avoided.  It  is  caused  by  the  wood's  dry- 
ing more  rapidly  at  the  ends  than  some  distance  from  the 
ends,  where  drying  takes  place  only  from  the  sides. 

Checks  on  the  face  of  lumber,  known  as  surface  checks, 
are  due  to  the  surface  drying  much  more  rapidly  than  the 
interior.  Wood  which  is  badly  surface-checked  splits  more 
easily  in  machining  and  nailing.  Timbers  containing  the  pith 
will  invariably  check  in  seasoning  because  the  shrinkage  in 
the  circumferential  direction  is  greater  than  toward  the 
center. 

Cupping — By  cupping  is  meant  the  curvature  of  lumber 
across  the  grain,  which  gives  it  more  or  less  of  a  trough-like 
appearance.  It  may  be  due  to  one  side  drying  more  rapidly 
than  the  other,  in  which  case  it  is  temporary.  Permanent 
cupping  takes  place  in  plain-sawed  lumber  when  dried  with 
insufficient  weight  on  it.  In  plain-sawed  lumber  the  side  to- 
ward the  center  of  the  tree  shrinks  less  in  width,  thus  causing 
the  lumber  to  curve  away  from  the  center  as  it  dries,  as 
illustrated  in  figure  4. 

Casehardening — By  casehardening  is  meant  a  condition  of 
internal  stress  in  seasoned  lumber  which  causes  it  to  cup  in- 
wardly when  resawed.  (See  figure  4B.)  Since  much  box 
lumber  is  resawed,  casehardening  gives  considerable  trouble 
in  the  box  industry. 

Honeycombing — In  some  casehardened  lumber  the  inter- 
nal stress  becomes  so  great  that  the  wood  is  torn  apart,  pro- 
ducing internal  checks  known  as  "honeycomb."  (See  figure 
6.)  These  checks  also  extend  along  the  medullary  rays  and 
may  come  to  the  surface. 

Color — The  manufacturer  of  boxes  and  crates  can  not 
pay  much  attention  to  tlve  color  of  the  wood  he  uses.  Light 
colored  woods  are  usually  preferable,  however,  because  ad- 
dresses and  advertising  matter  show  up  better  than  on  dark 
woods.  This  is  one  reason  why  pine  leads  as  a  box  material. 
For  certain  high-grade  containers  only  white  woods  are  used. 


26  WOODEN  BOX   AND    CRATE   CONSTRUCTION 

Odor  and  Taste — Containers  of  certain  kinds  of  food  must 
be  free  from  odor  or  taste  or  they  will  taint  the  contents.  It 
is  not  the  purpose  of  this  publication  to  discuss  which  foods 
are  and  which  are  not  easily  tainted.  The  following  species 
of  wood  have  a  pronounced  odor  and  should  not  be  used  for 
shipping  certain  classes  of  food:  all  of  the  cedars  (including 
arborvitae),  Alpine  fir,  yellow  pine,  and  sassafras. 

MECHANICAL    OR    STRENGTH    PROPERTIES    OF    WOOD1 

Meaning  of  Strength — Strength  in  the  broad  sense  of  the 
word  is  the  summation  of  the  mechanical  properties  of  a 
material,  or  its  ability  to  resist  stress  or  deformation.  While 
such  properties  as  hardness,  stiffness,  and  toughness  are  not 
always  thought  of  in  connection  with  the  term  "strength,"2 
they  are  unconsciously  included  when  in  a  specific  instance 
they  are  important.  Such  expressions  as  strength  in  shear, 
strength  in  compression,  and  strength  as  a  column  are  very 
specific  and  allow  little  chance  for  confusion.  (See  Tables 
6  and  7.) 

Tensile  Strength — The  tensile  strength  of  a  material  is 
measured  by  the  resistance  it  offers  to  forces  which  tend  to 
pull  it  apart.  In  wood,  tension  may  be  produced  along  the 
grain  or  across  the  grain.  The  tensile  strength  along  the  grain 
is  many  times  greater  than  it  is  across  the  grain.  It  is  almost 
impossible  in  ordinary  construction  to  develop  full  strength  in 
tension  along  the  grain  since  the  fastenings  are  usually  in- 
adequate ;  for  this  reason  tension  tests  along  the  grain  are  sel- 
dom made. 

Compression  Strength — The  strength  in  compression  is 
measured  by  the  resistance  a  material  offers  to  forces  which 
tend  to  crush  it.  In  wood,  these  forces  may  act  along  the 
grain  or  at  right  angles  to  it.  In  compression  parallel  to  the 
grain,  as  in  a  post,  wood  shows  great  strength.  In  compres- 
sion perpendicular  to  the  grain,  no  maximum  load  is  reached ; 
crushing  takes  place  as  the  load  is  increased.  Crushing 
strength  is  important  in  determining  the  size  of  bearing  areas 
in  heavy  crates. 

Shearing  Strength — By  shearing  strength  is  meant  the 
resistance  a  piece  of  wood  offers  to  a  force  which  tends  to 


Carious  values  have  been  combined  and  are  given  in  Table  1,  as  strength  as 
m  beam  or  post,  stiffness,  shock  resisting  ability,  and  hardness.  The  basis  for  de- 
riving these  values  is  given  in  Table  6. 

2Methods  of  determining  the  strength  values  of  wood  are  explained  in  Bulletin 
556,  Forest  Service,  U.  S.  Department  of  Agriculture. 


USE  OF  WOOD  IN  BOX  AMD  CRATE  CONSTkUCTON      2? 


slide  one  portion  of  it  over  the  other  portion.    It  varies  as  the 
area  of  the  plane  along-  which  the  shear  occurs.     Boxes  and 

TABLE  6.    PHYSICAL  AND  MECHANICAL  PROPERTIES  OF  WOODS  GROWN 
IN  THE  UNITED  STATES 

Manner    of    Obtaining    Composite    Figures    Used    in    Table    7 


Strength  as  a  beam  or  post1 

Hardness1 

Values  based  on 

Reduction 
factor2 

Weight3 

Values  based  on 

Reduction 
factor2 

Weight' 

Green 

Air-dry8 

Green 

Air-dry8 

Static  bending 
M.  of  R.4  
F.  S.  atE.  LA.. 

1.00 
1.80 

4 
2 

2 
'  1 

Comp.   perpendicu- 
lar to  grain  
End  hardness  

1.000 
.865 

4 
2 

2 
1 

Impact  bending 
F.  S.  atE.  LA.. 

.80 

•  2 

1 

Radial  hardness  .  .  . 
Tangential 

.930 

2 

1 

Comp.  parallel 

hardness 

950 

2 

1 

F.  S.  at  E.  LA  .  . 

2.8« 

2 

1 

Max.  cr.  str.6  

2.30 

4 

2 

Shock  resisting  ability1 

Stiffness1 

Values  based  on 

Reduction 
factor* 

Weight^ 

Values  based  on 

Reduction 
factor2 

Weight* 

Green 

Air-dry8 

Green 

Air-dry8 

Static  bending 

Static  bending 

Work  to  max.  load 

1.000 

4 

2 

M.ofEJ  

1.00 

4 

2 

Total  work  

.380 

2 

1 

Impact  bending 

Impact  bending 

M.ofEJ  

1.00 

2 

1 

Height  of  drop.  .  . 

.358 

4 

2 

Comp.  parallel 

M.  ofE.7  

1.00 

2 

1 

Shrinkage1 

Values  Based  on 

Weight' 

Volume  

2 

Radial  +  Tangential  

The  per  cent  shrinkage  in  volume  from  green  to  oven-dry  condition  is  based  on  volume  when  green. 

'Formulae  showing  relation  of  other  properties  shown  in  table  to  specific  gravity  (G): 
Strength  as  a  beam  or  post.  .20000  G 

Hardness 4300  G2.* 

Shock  resisting  ability 44 . 5  G2.° 

Stiffness 3000  G 

Shrinkage 26.5  G 

2The  reduction  factor  represents  the  average  ratio  of  the  first  property,  which  is  taken  as 
unity,  to  the  properties  listed  below  as  determined  by  the  average  of  all  species  tested  green. 

3The  weight  taken  into  account,  the  relative  importance  of  the  various  properties  included 
in  the  composite  values,  and  also  the  greater  reliability  of  the  values  based  on  green  tests  due  to  the 
greater  amount  of  data. 

4M.  of  R.— Modulus  of  rupture. 
*F.  S.  at  E.  L.— Fiber  stress  at  elastic  limit. 
8Max.  cr.  str. — Maximum  crushing  strength. 
7M.  of  E.— Modulus  of  elasticity. 

8The  air-dry  values  were  reduced  to  12  per  cent  moisture  by  the  following  approximate 
formulae,  which  may  be  used  within  narrow  limits: 

When  moisture  is  under  12  per  cent  When  moisture  is  above  12  per  cent 


6(AD-B)  +  B 

D12 

18-M 

D 12— Value  at  12  per  cent  moisture. 
AD — Value  air-dry  as  tested. 
M— Per  cent  moisture  as  tested. 


D12  - 


10(AD-B)  +  B 
22-M 


28 


WOODEN  BOX  AND   CRATE   CONSTRUCTION 


TABLE  7.    SOME  PHYSICAL  AND  MECHANICAL  PROPERTIES  OF  Box  WOODS, 

ON   THE   BASIS    OF   WHITE   PlNE1   AT    100 


KIND  OF  WOOD 

Specific  gravity 
oven-dry  wt. 
green  volume 

Shrinkage  in 
volume  from 
green  to  oven-dry 

Strength  as  a 
beam  or  post 

Hardness 

' 

Shock  resisting 
ability 

Stiffness 

Coniferous  species 
Pine,  white   (Pinus  strobus)  

Northern  white  cedar  
Cedar,  incense               

100 

(0.363) 
81 
91 

100 

(7.9) 
87 
103 

100 

(7340) 
74 
108 

100 

(363) 
79 
124 

100 

(6.00) 
80 
92 

100 

(1235) 
62 
89 

Cedar,  Port  Orford        

113 

147 

128 

143 

157 

140 

Cedar,  Western  red      .      ... 

85 

100 

96 

95 

87 

90 

Cypress,  bald                  .      .        .    . 

113 

138 

123 

132 

128 

113 

Douglas  fir  —  Washington  and 
Oregon  (coast  type) 

125 

161 

140 

154 

135 

151 

Douglas  fir  —  Montana  and 
Wyoming  (mount,  type)  
Fir,  Alpine 

112 

84 

130 
117 

112 

82 

135 
92 

114 
62 

114 

77 

Fir,  Amabilis 

103 

180 

103 

96 

117 

118 

Fir,  balsam 

92 

130 

87 

79 

85 

93 

Fir,  lowland  white 

102 

133 

107 

111 

119 

124 

Fir,  noble  

96 

173 

106 

97 

118 

123 

Fir,  white 

96 

130 

103 

116 

93 

106 

Hemlock   Kastern 

106 

128 

113 

134 

115 

101 

Hemlock,  Western  

110 

151 

121 

124 

108 

121 

Larch,  Western  

133 

163 

137 

165 

136 

123 

Pine,  jack 

108 

129 

95 

122 

136 

88 

Pine,  loblolly  
Pine,  lodgepole  
Pine,  longleaf  
Pine,  Norway  
Pine,  pitch  

139 
105 
152 
121 
129 

161 
144 
157 
147 
151 

137 

99 
164 
128 
112 

159 
107 
198 
125 
150 

160 
103 
175 
143 
162 

131 
103 
151 
132 
103 

Pine,  shortleaf  
Pine,  sugar  
Pine,  Western  white  
Pine,  Western  yellow  

136 
99 
108 
105 

146 
106 
146 
127 

138 
98 
110 
98 

169 
107 
98 
109 

157 
87 
121 
97 

125 
89 
123 
94 

Spruce,  Englemann  
Spruce,  red,  white,  sitka  
Tamarack  

86 
100 
135 

129 
155 
162 

82 
103 
128 

86 
106 
142 

77 
120 
145 

82 
108 
118 

crates  often  fail  on  account  of  nail  shear  at  the  ends  of  the 
boards  due  to  lack  of  shearing  strength  in  the  wood.  No 
values  for  shearing  strength  are  given  in  the  tables  in  this 
book. 

Strength  as  a  Beam — The  strength  of  a  beam  is  its  ability 
to  support  a  load.  The  strength  varies  inversely  as  the  length, 
directly  as  the  width,  and  directly  as  the  square  of  the  height. 


JThe  values  in  columns  2  to  6  are  based  on  composite  data  derived  as  indicated 
in  Table  6. 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      29 

TABLE  7.    SOME  PHYSICAL  AND  MECHANICAL  PROPERTIES  OF  Box  WOODS, 
ON  THE  BASIS  OF  WHITE  PiNE1  AT  100 — Concluded 


KIND  OF  WOOD 

Specific  gravity 
oven-dry  wt. 
green  volume 

T3 

se'S 
*S5 
««5 
3Sc 

SIS 

C/3  >  M 

Strength  as  a 
beam  or  post 

Hardness 

Shock  resisting 
ability 

Stiffness 

Hardwood  species 
Ash,  black  ... 

126 

182 

104 

164 

203 

98 

Ash,  pumpkin  

134 

143 

121 

270 

151 

94 

Ash,  white  
Aspen  

144 
99 

152 
137 

146 

85 

264 
80 

239 
134 

124 
79 

Basswood  

90 

200 

87 

78 

91 

100 

Beech  ,  
Birch,  paper  
Birch,  sweet  
Birch,  yellow  
Buckeye,  yellow  

150 
130 
162 
152 
90 

205 
203 
185 
211 
149 

137 
99 
152 
154 
81 

238 
132 
260 
214 

81 

216 
245 
257 
272 
90 

120 
93 
147 
144 
89 

Butternut 

99 

127 

89 

105 

137 

91 

Chestnut 

109 

141 

97 

130 

120 

89 

Cottonwood,  common 

102 

175 

89 

93 

122 

98 

Cucumber  tree  . 

121 

173 

125 

145 

173 

139 

Elm,  cork  ... 

158 

173 

145 

269 

317 

115 

Elm,  slippery  
Elm,  white  
Gum,  black  

134 
120 
127 

175 
180 
168 

128 
115 
114 

186 
151 
197 

272 
199 
141 

111 
98 
94 

Gum,  cotton  
Gum,  red  

125 
122 

154 
190 

119 
118 

204 
156 

143 
170 

102 
113 

Hackberry  
Magnolia  (evergreen)  
Maple,  red  
Maple,  silver  
Maple,  sugar  

134 
127 
134 
121 
154 

175 
154 
156 
144 
182 

104 
109 
132 
98 
154 

194 
209 
199 
170 

272 

249 
252 
177 
162 
204 

87 
108 
125 
85 
131 

Oak,  commercial  white  
Oak,  commercial  red  
Poplar,  yellow  
Sycamore  
Willow,  black  

162 
155 
102 
126 
96 

196 
186 
143 
173 
160 

137 
135 
99 
107 
61 

291 
263 
100 
169 
92 

214 
215 
94 
133 
165 

120 
131 
116 
103 
55 

For  instance,  a  10-foot  beam  is  half  as  strong  as  one  5  feet 
long;  a  plank  8  inches  wide  is  twice  as  strong  as  one  4  inches 
wide ;  a  board  1  inch  thick  is  four  times  as  strong  as  one 
Y-2  inch  thick,  quality  and  the  other  two  dimensions  being  the 
same  in  each  case. 

The  computed  stress  in  the  outermost  fibers  of  a  beam  at 
the  maximum  load  is  known  as  the  modulus  of  rupture.  The 
strength  of  these  extreme  fibers,  per  unit  of  cross-sectional 
area,  varies,  in  different  species  and  is  independent  of  the  di- 
mensions of  the  stick. 


JThe  values  in  columns  2  to  6  are  based  on  composite  data  derived  as  indicated 
jn  Table  6. 


30  WOODEN  BOX  AND   CRATE   CONSTRUCTION 

Stiffness — By  stiffness  is  meant  the  resistance  a  beam 
offers  to  bending.  It  varies  inversely  as  the  cube  of  the 
length,  directly  as  the  width,  and  directly  as  the  cube  of  the 
height.  For  instance,  a  5-foot  beam  is  eight  times  as  stiff  as 
one  10  feet  long;  a  plank  8  inches  wide  is  twice  as  stiff  as  one 
4  inches  wide ;  a  board  1  inch  thick  is  eight  times  as  stiff  as 
one  J/2  inch  thick. 

The  modulus  of  elasticity  is  a  measure  of  the  comparative 
stiffness  of  beams  of  the  same  dimensions  but  of  different 
species. 

Shock-resisting  Ability — Shock-resisting  ability,  often 
called  "toughness,"  is  important  in  box  and  crate  material. 
The  rough  handling  boxes  receive  makes  it  very  desirable 
that  box  woods  rank  high  in  enduring  shocks  without  break- 
ing, although  this  property  is  often  sacrificed  for  others  more 
important  commercially. 

Hardness — By  hardness  is  meant  resistance  to  indenta- 
tion. It  is  important  in  boxes  in  that  it  indicates  the  ease  with 
which  nails  may  be  over-driven  and  consequently  influences 
the  selection  of  nails  with  respect  to  size  of  head,  and  the  ease 
with  which  label  imprints  may  be  made  in  the  wood. 

Nail-holding  Power — By  nail-holding  power  is  meant  the 
maximum  resistance  to  be  overcome  in  pulling  nails  out  of 
wood.  If  the  nails  are  driven  into  the  side  grain  of  the  wood 
this  resistance  will  be  greater  than  if  they  are  driven  into 
the  end  grain.  (See  Table  10.) 

CARE  AND  SEASONING  OF  LUMBER  IN  STORAGE1 

It  is  usually  necessary  at  box  manufacturing  plants  to 
keep  on  hand  a  certain  supply  of  lumber  in  excess  of  imme- 
diate demands.  Such  stock  requires  care  to  prevent  deteri- 
oration and  to  promote  seasoning  as  much  as  possible.  Most 
of  the  seasoning,  however,  is  usually  done  at  the  sawmill  so 
as  to  avoid  paying  shipping  charges  on  the  excess  moisture. 
For  example,  if  wood  containing  74  parts  of  moisture  by 
weight  per  100  parts  of  dry  wood  is  dried  down  to  16  per  cent 
moisture  there  have  been  removed  58  parts,  or  one-third  of 
the  total  weight,  and  the  freight  charge  is  reduced  correspond- 
ingly. Occasionally  it  is  necessary  to  dry  stock  further  at  the 
factory. 

*For  a  more  detailed  discussion  of  this  subject  see  U.  S.  Department  of  Agri- 
culture Bulletin  552,  "The  Seasoning  of  Wood,"  by  H.  S.  Betts,  1917;  and  U.  S. 
Department  of  Agriculture  Bulletin  510,  "Timber  Storage  Conditions  in  the  Eastern 
and  Southern  States  with  Reference  to  Decay  Problems,"  by  C.  J.  Humphrey,  1917. 
These  may  be  obtained  from  the  Superintendent  of  Documents,  Government  Printing 
Office,  Washington,  D.  C.,  at  10  cents  and  20  cents,  respectively. 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      31 

POSSIBLE   DETERIORATION  IN  STORED  LUMBER 

Checking  at  Ends  and  on  Surfaces — Although  checking 
is  always  a  possible  cause  of  deterioration  in  stored  lumber, 
the  woods  which  are  most  commonly  used  for  boxes  and 
crates,  namely,  conifers  and  light  hardwoods,  do  not  check  so 
badly  as  some  of  the  heavier  hardwoods. 

Twisting  and  Cupping — Lumber  which  is  not  straight 
causes  more  or  less  trouble  in  manufacture  and  sets  up 
stresses  in  the  finished  box  when  it  is  nailed  down  in  a  flat 
position.  These  difficulties  can  be  largely  avoided  by  proper 
piling  of  the  lumber. 

Casehardening,  Honeycombing,  and  Collapse — Casehard- 
ening,  honeycombing,  and  collapse  do  not  develop  seriously  in 
the  air-drying  of  most  woods  used  for  boxes.  Oak,  especially 
in  the  South,  is  apt  to  caseharderi  and  honeycomb  when  ex- 
posed to  summer  atmospheric  conditions. 

Blue  Stain  or  Sap  Stain — Blue  stain,  or  sap  stain,  is  a 
blue  discoloration  of  the  sapwood.  It  is  very  common  in  the 
pines  and  red  gum  and  occurs  also  in  the  sapwood  of  other 
species.  .  Blue  stain  is  due  to  a  fungous  growth,  which  jives 
on  the  sap  in  the  cells,  does  not  destroy  the  wood  or  injure  its 
strength,  and  is  objectionable  only  on  account  of  the  discol- 
oration it  produces.  Badly  stained  pieces  may  make  the 
presence  of  decay  hard  to  detect. 

The  fungus  producing  blue  stain  may  occur  in  the  log, 
but  it  occurs  more  commonly  in  freshly-sawed  lumber.  It  can 
thrive  only  as  long  as  the  sapwood  is  moist;  therefore,  pil- 
ing the  lumber  so  that  it  will  season  as  rapidly  as  possible 
greatly  reduces,  though  it  does  not  prevent,  this  discoloration. 
Blue  stain  makes  rapid  progress  in  green  lumber  during  warm 
humid  weather,  especially  when  the  lumber  is  close-piled,  as 
it  usually  is  in  transit.  Under  such  conditions  the  stain  may 
penetrate  all  of  the  sapwood  in  a  few  days.  Blue  stain  can 
be  prevented  by  kiln-drying  the  lumber  immediately  after 
sawing;  this  is  ordinarily  done  only  with  the  higher  grades, 
although  some  lumber  mills  also  run  the  lower  grades  of  lum- 
ber through  a  kiln.  Another  preventive  measure  consists  in 
dipping  the  lumber  as  it  comes  from  the  saw  in  an  antiseptic 
solution,  such  as  sodium  carbonate. 

Decay  or  Rot — Decay  is  due  to  fungous  growth  which 
destroys  the  wood  substance.  In  order  that  decay  may  take 
place,  the  wood  must  be  moist  and  the  temperature  not  too 


32  WOODEN   BOX  AND    CRATE   CONSTRUCTION 

cold.  Wood  dried  to  below  20  per  cent  moisture  rarely  de- 
cays; therefore,  box  lumber  dried  to  from  12  to  18  per  cent 
moisture  is  practically  immune  from  decay  as  long  as  it  re- 
mains in  that  condition.  Although  decay  is  not  so  rapid  in 
its  action  as  sap  stain,  it  may  seriously  reduce  the  strength 


FIG.  8 — Method  of  measuring  twisting  of  plywood. 

of  some  woods  in  3  or  4  months  during  warm  weather,  espe- 
cially when  close-piled.  Decay,  including  the  so-called  dry 
rot,  can  be  prevented  in  stored  lumber  by  properly  piling  the 
lumber  some  distance  above  the  ground. 

Insect  Attack — Certain  woods  are  subject  to  insect  attack 
when  insufficiently  seasoned.  The  sapwood  of  some  seasoned 
hardwoods  is  subject  to  attack  by  an  insect  known  as  the 
powder-post  beetle.  Hickory,  ash,  and  oak  are  most  subject 
to  this  injury,  but  butternut,  maple,  elm,  poplar,  sycamore, 
and  others  are  also  attacked.  Containers  made  from  such 
lumber  should  not  be  used  in  foreign  trade  because  some 
countries  will  not  allow  such  packages  to  enter  for  fear  of  the 
introduction  of  injurious  insects. 

Proper  Methods  of  Piling  Lumber  in  the  Yard — The 
expense  which  it  is  advisable  to  incur  in  equipping  a  lumber 
yard  for  proper  air  seasoning  of  lumber  depends  largely  on 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      33 


the  permanency  of  its  location.  The  small  amount  of  addi- 
tional work  required  for  properly  piling  lumber  so  as  to 
shorten  the  time  required  for  seasoning  and  reduce  deteriora- 
tion is  usually  well  worth  while.  Lumber  thrown  on  the 
ground  promiscuously,  or  piled  on  sagged  foundations  with 
loose  projecting  ends,  will  surely  depreciate  in  value  in  a 
comparatively  short  time. 


FIG.  9 — Lumber  piled  sidewise  on  concrete  and  metal  foundations. 

A  lumber  yard  should  be  well  drained,  and  so  situated 
and  divided  up  by  alleys  as  to  reduce  the  cost  of  handling 
the  lumber  to  a  minimum. 

Box  lumber  is  practically  always  piled  flat ;  it  may  lie 
with  the  ends  of  the  boards  toward  the  alley  (endwise  pil- 
ing), or  parallel  with  the  alley  (sidewise  piling),  as  shown  in 
figure  10.  In  either  case  the  piles  slope  from  front  to  rear, 
away  from  the  alley.  Endwise  piling  is  more  common  be- 
cause it  facilitates  handling  of  the  lumber  and  because  of  the 
better  visual  inspection  from  the  alley  which  it  affords.  Side- 
wise  piling  has  the  advantage  of  giving  better  air  circulation 
from  side  to  side,  and  what  moisture  enters  the  piles  runs 
across  the  boards  instead  of  running  lengthwise  and  accumu- 
lating under  the  stickers  as  in  end-piling. 


34 


WOODEN   BOX   AND    CRATE   CONSTRUCTION 


FIG.   10 — A   well-kept   lumber  yard  maintained   by  a   large   eastern   wood- 
using    factory.       (Note    forward    pitch  'of    stacks,    treated 
ends,  and  general  sanitary  ground  conditions.) 


FIG.  11 — Side  view  of  lumber  piled  endwise  to  the  alley  with  skids  resting 
directly  on  the  piers. 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      35 

Foundations  and  Skids — Strong  and  durable  foundations 
should  be  provided  for  the  lumber  piles.  The  best  kind  of 
foundation  consists  of  piers  of  concrete  or  masonry,  as 
shown  in  figures  9  and  11.  If  this  form  of  construction  is  not 
feasible,  creosoted  wooden  posts,  or  creosoted  blocks,  or  sup- 
ports of  very  durable  woods  may  be  used.  Never  use  un- 
treated sapwood  or  even  heartwood  of  non-durable  woods  in 
the  foundations  except  for  very  temporary  purposes. 

The  tops  of  these  foundations  should  be  level  in  the  direc- 
tion parallel  to  the  alley  but  sloping  from  front  to  rear  1  inch 
for  every  foot.  The  top  of  the  lowest  foundations  should  be 
sufficiently  high  so  that,  allowing  for  cross-pieces  over  the 
piers,  the  lumber  will  be  at  least  18  inches  from  the  ground. 
Weeds  and  other  obstructions  to  circulation  should  be  re- 
moved from  around  the  piles. 

The  distance  between  piers  crosswise  of  the  pile  varies 
with  the  thickness  of  skids  used,  but  should  be  such  as  to 
avoid  any  sagging  in  the  skids. 

The  distance  between  piers  parallel  with  the  pile  depends 
on  whether  the  cross  pieces,  or  skids,  are  laid  directly  on  the 
piers,  figure  10,  or  on  beams  placed  on  the  piers  parallel  to 
the  pile,  figure  11.  If  the  first  method  is  used  the  distance 
between  piers  must  be  the  same  as  between  subsequent  stick- 
ers, for  the  stickers  must  be  aligned  over  the  skids  on  the 
piers.  This  distance  should  not  exceed  4  feet,  and  for  lumber 
that  warps  easily,  it  must  be  less.  If  the  last  method  is  used 
in  which  the  skids  rest  on  strong  beams  laid  on  the  piers 
parallel  with  the  pile,  fewer  piers  need  be  built;  this  method 
also  permits  changing  the  spacing  of  the  skids  and  stickers 
for  different  kinds  of  lumber,  and  is  especially  recommended 
for  red  gum,  black  gum,  and  cotton  gum  (tupelo)  for  which 
it  is  best  to  have  the  stickers  about  2  feet  apart. 

For  the  beams  and  skids  steel  I-beams  or  inverted  rail- 
road rails  securely  imbedded  in  the  foundation  are  most  per- 
manent. Creosoted  timbers,  or  naturally  durable  woods,  are 
also  very  satisfactory.  If  the  wood  is  given  no  preservative 
treatment,  its  life  will  be  increased  somewhat  by  applying  two 
coats  of  hot  creosote  at  all  points  of  contact.  Untreated  sap- 
wood  so  close  to  the  ground  will  decay  in  a  comparatively 
short  time  and  may  infect  the  lumber. 

Stickers — The  stickers  should  be  of  heartwood,  prefer- 
ably of  some  durable  species,  dressed  on  one  side  to  uniform 
thickness  and  not  over  4  inches  wide.  Narrower  widths  are 


36  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

recommended.  It  is  very  poor  policy  to  use  regular  widths 
of  lumber  for  cross  pieces  within  the  piles  because  little  or 
no  drying  takes  place  where  large  areas  are  covered  up,  and 
decay  may  set  in.  The  stickers  should  be  %  inch  thick  for 
inch  lumber  and  up  to  \y>  inches  for  thicker  stock;  they 
should  be  slightly  longer  than  the  width  of  the  pile. 

The  front  and  rear  stickers  should  be  flush  with  or  pro- 
trude slightly  beyond  the  front  and  rear  of  the  lumber  piles. 
The  other  stickers  should  be  placed  in  alignment  over  the 
skids  and  parallel  to  the  front  of  the  lumber  pile. 

Placing  of  Lumber — If  possible,  different  lengths  of  lum- 
ber should  be  put  in  separate  piles.  No  loose  and  unsup- 
ported ends  should  be  permitted.  A  space  of  about  1  inch 
should  be  left  between  the  edges  of  1-inch  boards  in  each 
course,  and  2  inches  between  2-inch  boards.  Lumber  piled  in 
the  open  should  have  each  course  project  slightly  over  the 
course  beneath  on  the  front  side  of  the  pile  so  as  to  provide 
a  forward  pitch  to  the  high  end  of  the  stack.  For  wide  piles 
it  is  recommended  that  a  vertical  open  space  or  flue  be  left 
in  the  middle  of  the  pile,  about  the  width  of  a  board,  extend- 
ing upward  from  the  skid  two-thirds  the  height  of  the  pile. 

The  top  of  the  lumber  pile  should  be  closed  with  over- 
lapping boards  laid  so  as  to  drain  off  all  water.  It  is  also 
desirable,  especially  for  the  better  grades  of  lumber,  to  have 
this  covering  or  roof  project  on  all  sides  of  the  pile  so  as  to 
keep  out  some  of  the  snow  and  rain,  and  produce  shade  for 
the  sides  and  ends. 

Size  and  Spacing  of  Piles — Lumber  piles  are'  usually 
built  from  8  to  16  feet  wide.  The  height  depends  on  the 
character  of  the  lumber,  and  the  'extent  to  which  the  yard  is 
crowded.  The  space  between  piles  should  not  be  less  than 
two  feet;  four  or  five  feet  is  better  if  yard  conditions  permit. 

Kim-Drying  Box  Lumber1 — Lumber  1  inch  thick  requires 
from  2  months  to  a  year  for  air-drying,  but  the  green  stock 
can,  as  a  rule,  be  kiln-dried  for  box  purposes  in  from  2  to  10 
days.  Veneer  or  rotary-cut  lumber  T3g  inch  thick  requires 
from  6  to  12  days  for  air-drying;  the  same  material  can  be 
kiln-dried  in  about  12  hours.  Kiln-drying  at  the  saw  mill 


^or  information  on  the  principles  of  kiln-drying  and  the  operation  of  kilns  see: 
Forestry  Bulletin  104 — The  Principles  of  Drying  Lumber  at  Atmospheric  Pressure, 
and  Humidity  Diagram,  by  H.  D.  Tiemann  ;  U.  S.  Department  of  Agriculture  Bulletin 
552 — The  Seasoning  of  Wood,  by  H.  S.  Betts  ;  and  U.  S.  Department  of  Agriculture 
Bulletin  509 — The  Theory  of  Drying  and  Its  Application  to  the  New  Humidity  Regu- 
lated and  Recirculating  Dry  Kiln,  by  H.  D.  Tiemann ;  The  Kiln  Drying  of  Lumber, 
by  H.  D.  Tiemann,  J.  B.  Lippincott  &  Co.,  Philadelphia,  Pa. 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      37 

also  prevents  deterioration  of  the  lumber,  especially  blue 
stain. 

The  saving  in  time  by  kiln-drying  greatly  reduces  the 
amount  of  stock  it  is  necessary  to  carry  in  the  yards.  On  the 
other  hand,  the  cost  of  kiln  equipment  and  the  expense  of 
kiln  operation  offset  to  some  extent  the  advantages  so  gained. 

In  deciding  whether  it  pays  to  kiln-dry  lumber  instead  of 
air-drying  it,  the  following  factors  should  be  considered : 

Air-Drying  Kiln-Drying 

Interest     on     capital     invested    in          Interest    on     capital     invested     in 
ground    occupied    by    lumber    yard,       ground  occupied  by  kilns  and  track- 
yard     equipment,     and     the     large      age,    dry   kilns,    and    equipment,    in- 
amount  of  lumber  kept  in  storage.          eluding   extra   boiler   capacity,    stor- 
age  sheds,   and  a   small   amount   of 
Taxes  on  land  and  equipment.  lumber  kept   in   storage. 

Taxes  on  land,  kilns,   sheds,  and 
Insurance  on  equipment  and  lum-       equipment. 

her.  Insurance  on  buildings,  equipment 

and   a    comparatively    small    amount 
Depreciation  of  lumber  and  equip-       of  lumber. 

ment.  Depreciation    of    buildings,    equip- 

ment and  lumber. 

Cost  of  handling  lumber  from  the  Cost  of  handling  lumber  from  the 
time  it  is  received  until  ready  for  time  it  is  received  until  ready  for 
shipment  or  manufacture.  shipment  or  manufacture. 

Cost  of  operating  of  kilns :  attend- 
ance, fuel,  water,  etc. 

THE  USE  OF  VENEER  IN  THE  CONSTRUCTION  OF 
PACKING  BOXES 

Definition — Veneer  is  a  thin  sheet  of  wood.  There  is  no 
standard  thickness  above  which  it  is  called  lumber.  The 
common  practice  is  to  use  the  term  veneer  for  all  stock  which 
has  been  cut  on  special  veneer  machinery,  and  lumber  for  that 
which  is  cut  with  ordinary  circular  or  band  saws. 

Although  originally  veneer  was  cut  from  high-priced  cab- 
inet woods  to  save  material,  it  is  now  cut  extensively  from 
common  species,  and  is  used  for  many  purposes  when  light- 
ness rather  than  beauty  is  the  principal  requisite.  It  is  well 
suited  for  the  manufacture  of  small  packages  and  even  pack- 
ing boxes  of  considerable  size  because  of  its  light  weight  and 
the  small  amount  of  wood  required  for  construction  of  this 
kind. 

MANUFACTURE  OF  VENEER 

Method  of  Cutting — Most  of  the  veneer  used  at  present 
in  box  manufacture  is  resawed,  rotary-cut,  or  sliced.  The 
rotary  and  sliced  methods  reduce  the  waste  and  produce  wide 


38  WOODEN  BOX   AND    CRATE   CONSTRUCTION 

stock.  The  veneer  thus  produced  is  comparatively  free  from 
defects,  as  only  relatively  smooth  logs  can  be  used  for  this 
purpose.  Such  material  is  cut  with  a  special  thin-edged 
veneer  saw,  a  knife,  or  an  ordinary  band  saw. 

Drying — Veneer,  like  other  forms  of  lumber,  should  be 
properly  dried  in  order  to  give  satisfactory  service.  Drying 
is  sometimes  done  in  the  open  air  in  open  sheds,  the  time 
required  varying  from  several  days  to  several  weeks,  depend- 
ing on  the  kind  and  thickness  of  the  stock  and  weather  con- 
ditions. This  thin  material  may  be  dried  in  a  kiln,  in  which 
case  it  must  be  weighted  down  to  keep  it  straight.  It  is  often 
put  through  progressive  driers  which  dry  the  wood  in  from 
several  minutes  to  an  hour.  These  driers  consist  of  long 
chambers  with  a  series  of  belts  or  live  rolls  on  which  the 
veneer  is  carried  through  the  apparatus.  The  temperature  is 
comparatively  high  and  the  humidity  low,  so  that  rapid  dry- 
ing results.  There  is  little  danger  of  casehardening  very  thin 
stock.  Another  type  of  drier  consists  of  a  series  of  heated 
iron  plates  between  which  the  material  is  pressed.  These 
plates  separate  at  regular  intervals  so  as  to  allow  the  mate- 
rial to  shrink. 

WOODS  USED  FOR  Box  VENEERS 

Thin  lumber  is  made  from  many  kinds  of  woods,  includ- 
ing most  of  our  commercial  species,  but  red  gum  leads  all 
others  in  quantity  used.  Yellow  pine  and  maple  are  also  used 
largely  in  the  manufacture  of  boxes,  baskets,  and  crates.  Cot- 
tonwood  is  a  very  desirable  species  for  use  in  the  production 
of  veneer  because  it  gives  very  little  trouble  in  cutting.  The 
sides  and  bottoms  of  cracker  boxes  and  light  egg  cases  are 
made  principally  of  cottonwood  stock.  Elm  is  used  largely 
for  cheese  boxes.  Other  species  commonly  used  for  thin 
stock  in  box  and  package  manufacture  are  birch,  beech,  cot- 
ton gum  (tupelo),  basswood,  sycamore,  and  Douglas  fir;  and 
many  other  commercial  species  are  used  to  a  smaller  extent. 

Although  very  definite  statistics  are  not  available  as  to 
the  amount  of  thin  lumber  used  for  boxes  and  fruit  and  vege- 
table packages,  it  is  estimated  that  out  of  the  total  6  bil- 
lion board  feet  of  lumber  annually  used  by  the  box  industry, 
700  million  feet  log  scale  is  used  for  thin  stock.  The  use  of 
thin  lumber  is  gradually  increasing. 

Most  of  the  thin   lumber  or  veneer  used  in  boxes   and 


USE  OF  WOOD  IN  BOX  AND  CRATE  CONSTRUCTON      39 

crates  is  in  single  thicknesses  securely  fastened  to  relatively 
thick  ends  or  cleats. 

Examples  of  the  use  of  single-thickness  stock  for  ship- 
ping containers  are  very  common.  T-he  cheese  box  is  one  of 
the  oldest  forms.  Vegetable  barrels,  baskets,  berry  boxes, 
fruit  crates,  cracker  boxes,  egg  cases,  canned  goods  boxes, 
and  many  others,  including  a  special  type  known  as  wire- 
bound  boxes,  are  used  extensively. 

Use  of  Plywood  in  Packing  Boxes — The  properties  of 
veneer  or  thin  lumber  in  single  thicknesses  are  improved  by 
gluing  together  three  or  more  sheets  with  the  grain  crossing. 
The  product  is  known  as  "plywood,"  and  has  the  advantage 
of  producing  a  comparatively  strong  and  light  piece  of  mate- 
rial in  which  the  strength,  stiffness  and  shrinkage  along  and 
across  the  grain  of  the  face  pieces  are  more  nearly  equal  than 
in  lumber.  Plywood  also  has  greater  resistance  to  splitting 
in  nailing  and  to  puncturing  in  handling. 

Plywood  is  not  used  very  extensively  in  the  manufacture 
of  boxes,  but  it  has  distinct  advantages  over  other  forms  of 
wood  construction.  A  box  properly  made  of  plywood  is  ex- 
ceedingly strong  for  its  weight.  The  principal  objection  to 
the  more  extended  use  of  plywood  in  boxes  is  the  cost  in- 
volved in  gluing  up  of  the  thin  sheets. 

Plywood  should  be  made  up  of  an  odd  number  of  plies 
with  the  grain  of  successive  plies  at  right  angles  to  each  other. 
The  construction  on  the  two  sides  of  the  core  should  be  sym- 
metrical as  to  species,  thickness  of  panels,  and  direction  of 
grain.  The  strength  in  bending  is  less  in  the  direction  paral- 
lel to  the  grain  of  the  face  pieces,  and  greater  at  right  angles 
to  the  grain  of  the  face  pieces  than  in  boards  of  the  same 
thickness  and  same  kind  of  wood.  A  combination  of  faces  of 
strong  wood  and  a  thick  core  of  a  light  wood  gives  greater 
strength  in  bending  than  the  same  faces  with  a  thinner  core 
of  the  same  weight  of  some  heavier  species.  The  glued  sur- 
faces are  not  so  likely  to  separate  in  plywood  constructed 
with  thin  plies  as  in  that  made  of  thicker  material. 

Plywood  does  not  split  in  nailing  so  easily  nor  does  it 
puncture  so  easily  as  a  single  board  of  the  same  thickness,  the 
resistance  increasing  with  the  number  of  plies.  The  greater 
the  number  of  plies,  the  straighter  the  plywood  wrill  remain 
with  change  in  moisture  content.  Plywood  in  outdoor  service 
will  cup  and  twist  least  if  it  has  a  moisture  content  of  from 
10  to  15  per  cent  when  it  comes  from  the  glue  press. 


CHAPTER  II 
BOX  DESIGN 

FACTORS  INFLUENCING  DETAILS  OF  DESIGN — CHARACTERISTICS  OF 
THE  VARIOUS  STYLES  OF  BOXES — FACTORS  DETERMINING  THE 
AMOUNT  OF  STRENGTH  REQUIRED — FACTORS  DETERMINING 
THE  SlZE  OF  A  BOX SPECIAL  CONSTRUCTIONS. 


Box  design  may  be  defined  as  the  development  of  definite 
details  for  constructing  boxes  which  will  deliver  their  con- 
tents to  the  purchaser  in  a  satisfactory  condition  and  at  a 
minimum  cost.  The  construction  of  more  expensive  boxes 
can  not  be  justified  unless  they  are  to  serve  as  an  advertise- 
ing  medium  or  perform  some  other  service  which  warrants 
the  additional  cost.  Among  the  factors  which  affect  box 
economy  is  the  cost  of  the  following:  raw  materials,  manu- 

TABLE  8.    THICKNESSES  OF  Box  BOARDS  OBTAINED  BY  RESAWING  OR  DRESS- 
ING 4/4  TO  7/4-INCH    LUMBER1 


Box  boards,  thickness 
Inches 

Rough  lumber,  thickness2 
Inches 

3/16  rough  or  SIS 

3  pieces  from  4/4 

1/4    rough  or  SIS 

3  pieces  from  4/4 

5/16  rough  or  SIS 

3  pieces  from  5/4 

3/8    rough  or  SIS 

2  pieces  from  4/4 

7/16  rough  or  SIS 

2  pieces  from  4/4 

1/2    rough  .or  SIS 

2  pieces  from  5/4 

9/16  rough  or  SIS 

2  pieces  from  5/4 

5/8    rough  or  SIS 

2  pieces  from  6/4 

11/16  rough 

2  pieces  from  6/4 

11/16  SIS 

2  pieces  from  7/4 

3/4    rough  or  SIS 

2  pieces  from  7/4 

13/16  rough,  SIS,  or  S2S 

1  piece    from  4/4 

7/8    rough,  SIS,  or  S2S 

1  piece    from  4/4 

15/16  rough  or  SIS 

1  piece    from  4/4 

4/4    rough 

1  piece    from  4/4 

4/4    SIS 

1  piece    from  5/4 

If  box  parts  are  to  be  dressed  on  two  sides  (S-2-S)  and  to  be  full  thick- 
ness also,  use  next  thickness  of  lumber  except  where  specified  in  above  table. 


Adopted  by   the  National   Association   of   Box   Manufacturers — August   5,    1915. 
2If     full     thickness     without    variation     is     required,     then    use     the     next    greater 
thickness. 

40 


BOX    DESIGN 


41 


facturing  (including  assembling),  handling,  storage,  freight, 
and  losses  due  to  box  failures.  A  designer  of  boxes  should 
endeavor  to  gain  a  knowledge  of  all  these  phases  of  the 
problem. 

FACTORS   INFLUENCING   DETAILS   OF   DESIGN 

LUMBER  AND  VENEER 

Availability  and  Supply — Lumber  of  suitable  thickness 
for  box  construction  is  usually  obtained  by  resawing  regular 
sizes  of  low  grade  stock,  although  in  some  sections  the  logs 
are  sawed  directly  into  lumber  of  the  desired  thicknesses. 

The  designer  should  have  definite  information  regarding 
the  properties,  grades,  widths,  thicknesses,  lengths,  supply, 
and  cost  of  lumber  of  the  species  available  where  the  box  is 
to  be  manufactured  and  the  commodity  for  which  the  box  is 
made,  and  the  manner  in  which  the  commodity  is  to  be 
packed.  Data  showing  what  thicknesses  can  be  obtained 
from  commercial  lumber  by  resawing  and  surfacing  should 
be  at  hand.  (See  Tables  8  and  9.)  The  dimensions  of  mate- 

TABLE  9.     STANDARD  THICKNESSES  OF  HARDWOODS 

Adopted  by  the  National  Hardwood  Lumber  Association  and  the  Amer- 
ican  Hardwood  Manufacturers'  Association.1 


Rough  thickness 
Inches 

Surfaced  thickness 
Inches 

3/8  S-2-S  to 

3/16 

1/2  S-2-S  to 

5/16 

5/8  S-2-S  to 

7/16 

3/4  S-2-S  to 

9/16 

1           S-2-S  to 

13/16 

1  1/4  S-2-S  to 

1     3/32 

1  1/2  S-2-S  to 

1   11/32 

1  3/4  S-2-S  to 

1     1/2 

2           S-2-S  to 

1     3/4 

2  1/2  S-2-S  to 

2     1/4 

3           S-2-S  to 

2     3/4 

3  1/2  S-2-S  to 

3     1/4 

4           S-2-S  to 

3     3/4 

Lumber  surfaced  on  one  side  only  must  be  1/16  inch  full  of  the  above 
thickness. 

rial  in  boxes  made  of  sawed  lumber  must,  if  not  inconsistent 
with  other  requirements,  be  such  as  will  use  the  material  with 
the  least  waste  in  resawing,  surfacing  and  cutting  to  size. 


formerly    iho    Hardwood    Manufacturers'    Association. 


42  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

The  main  waste  is  due  to  trimming  to  required  length  and 
width  and  at  the  same  time  eliminating  checked  ends,  splits, 
loose  and  rotten  knots,  and  knot  holes.  Rotary-cut  veneer 
can  be  obtained  in  lengths  up  to  60  inches  and  in  any  width 
that  can  be  readily  handled. 

Cost — The  actual  cost  of  lumber  is  not  the  purchase  price, 
but  the  cost  of  the  usable  material  after  due  credit  has  been 
allowed  for  salvage  of  waste.  Obviously  it  is  important  that 
the  amount  of  waste  which  occurs  in  the  various  grades  of 
material  be  accurately  known  to  the  designer. 

MANUFACTURING  LIMITATIONS 

Equipment — Design  will  necessarily  be  influenced  by  the 
box-making  equipment  available.  Equipment  for  making  the 
common  types  of  boxes  is  more  or  less  standardized.  Ac- 
curate information  on  the  kind  and  cost  of  each  operation 
performed  and  the  quantity  of  work  produced  by  each  ma- 
chine is  therefore  requisite  to  the  design  of  such  a  box  as  wil) 
cost  the  least  to  manufacture. 

Details  which  require  the  installing  of  special  machinery 
for  their  execution  should  be  avoided  if  possible,  unless  they 
are  improvements  of  such  a  character  that  there  will  be  a 
continued  demand  for  their  application.  The  experience  of 
the  Forest  Products  Laboratory,  however,  is  that  in  a  large 
majority  of  cases  the  common  designs  of  boxes  are  the  more 
efficient  and  that  the  special  features  in  other  designs  usually 
interfere  with  balanced  construction. 

Cost  of  Operation — The  cost  of  various  machine  oper- 
ations depends  on  numerous  factors  such  as  general  factory 
overhead  charges,  depreciation  on  machines,  power  charges, 
cost  of  tools,  operator's  wages,  and  volume  of  work  done. 
The  standardization  of  box  and  crate  design  has  proved  one 
of  the  chief  factors  in  the  reduction  of  cost  of  manufacture. 
Unusual,  styles  or  special  features  always  increase  the  cost 
and  as  a  rule  decrease  the  serviceability  of  shipping  containers. 

Styles  of  Boxes — There  are  a  number  of  styles  of  nailed 
wooden  boxes  so  universally  used  that  they  may  be  called 
standard  nailed  boxes.  (See  Plate  III.) 

Many  special  styles  of  boxes  have  been  developed  for 
particular  conditions  and  commodities.  Whether  or  not  a 
box  which  can  be  returned  and  refilled  should  be  adopted  for 
carrying  a  commodity  depends  wrholly  upon  the  economic 


BOX   DESIGN  43 

phases  of  the  problem.  If  box  materials  continue  to  increase 
in  cost,  the  use  of  returnable  boxes  will  no  doubt  increase. 
Returnable  boxes  should,  so  far  as  possible,  be  made  collaps- 
ible, as  they  will  then  occupy  less  space  in  shipment  and 
storage  when  empty. 

Under  some  conditions  boxes  which  can  be  easily  and 
quickly  opened  are  demanded.  This  requirement  has  been 
especially  urgent  in  many  of  the  United  States  Army  Ord- 
nance boxes.  Types  of  such  easily-opened  boxes  are  shown 
in  Plate  IV. 

BALANCED  CONSTRUCTION  AND  FACTORS  AFFECTING  STRENGTH1 

When  all  elements  in  the  construction  of  a  box  resist 
equally  the  destructive  hazards  of  service,  it  is  balanced  in 
construction.  A  box  may  be  balanced  in  construction  and  yet 
be  excessively  heavy,  too  strong,  and  uneconomical  in  the  use 
of  material ;  or  it  may  be  too  light  and  weak  for  service.  With 
unbalanced  boxes  which  render  satisfactory  service  there  is 
frequently  a  waste  of  material  in  the  stronger  parts ;  and  an 
equally  or  even  more  serviceable  box  may  be  obtained  by 
reducing  the  strength  of  the  stronger  parts  until  they  are  in 
balance  with  the  weaker  parts.  This  is  because  the  parts 
which  are  excessively  heavy  transmit  an  undue  amounj;  of  the 
shocks  and  stresses  to  the  lighter  parts,  thus  causing  the 
lighter  parts  to  fail  sooner.  With  a  balanced  box  there  is  a 
more  even  distribution  and  absorption  of  stresses  and  shocks. 
Excessive  thickness  of  lumber  in  sides,  top,  or  bottom  of  a 
box  will  also  produce  undue  stresses  in  the  nails  and,  under 
certain  conditions,  will  be  a  source  of  weakness. 

The  chief  problem  in  box  design  is  to  detail  the  parts  so 
that  balanced  construction  and  proper  strength  are  both' 
obtained,  and  at  minimum  cost.  Balanced  construction  and 
a  proper  degree  of  strength  can  be  determined  by  suitable 
methods  of  testing.2 

Width  of  Stock  and  Joints — Stock  which  is  wide  enough 
to  make  one-piece  box  parts  has  various  advantages  in  com- 
parison with  narrower  stock.  Joints  which  would  otherwise 
occur  are  avoided,  thus  increasing  the  rigidity  of  the  boxes 
and  their  resistance  to  "weaving  action."  In  boxes  of  Style  1, 


1For  strength  data  on  various  types  of  boxes,  see  Forest  Service  Circular  No. 
214,  obtainable  from  the  Superintendent  of  Documents,  Washington,  D.  C.,  at  five 
cents  a  copy. 

2See  chapter  IV,  page  87. 


44  WOODEN   BOX  AND   CRATE   CONSTRUCTION 

Plate  III,  having  no  cleats  but  single-piece  ends  or  two-piece 
with  corrugated  fasteners,  it  is  very  desirable  to  have  one- 
piece  sides  because  they  diminish  the  liability  to  failure  and 
make  a  more  dependable  construction.  A  tighter  box  is  in- 
sured with  single-piece  parts.  Larger  knots  can  be  permitted 
in  boxes  with  single  piece  parts  because  the  allowable  sizes  of 
knots  bear  a  direct  ratio  to  the  width  of  the  board.  Single- 
piece  parts  reduce  machine  and  labor  costs ;  but  if  required 
exclusively,  they  would  greatly  increase  material  costs. 

When  two  or  more  pieces  are  used  in  any  part,  the  abut- 
ting edges  are  usually  tightly  joined.  This  may  be  accom- 
plished in  several  ways ;  the  simplest  form  of  joint  between 
the  edges  of  two  boards  is  shown  in  figure  1,  Plate  XV.  The 
abutting  edges  of  the  pieces  should  be  straight  and  square 
with  their  faces,  and  in  contact  throughout  so  as  to  make  a 
tight  joint. 

When  some  other  than  the  butt  joint  is  used  for  joining 
edges  of  boards,  it  is  called  a  matched  joint.  One  type  of 
matching  which  is  used  to  a  limited  extent  in  box  construc- 
tion when  the  lumber  is  ^  inch  or  more  in  thickness 
is  shown  by  figure  6,  Plate  XV.  Such  lumber,  known 
as  shiplap,  milled  to  join  in  this  way,  can  be  obtained  in  vari- 
ous widths,  and  this  is  undoubtedly  the  reason  why  it  some- 
times appears  in  box  construction.  It  is  not  as  effective  for 
tight  construction  as  other  matched  joints  since  the  adjacent 
boards  can  bend  independently. 

The  matched  joint  illustrated  by  figure  5,  Plate  XV,  is 
very  commonly  used  for  joining  box  boards.  In  addition  to 
matching,  the  pieces  may  be  glued  or  fastened  together  with 
corrugated  fasteners.  This  construction  makes  it  possible, 
when  the  material  is  over  ^  inch  thick,  for  the  weaker  boards 
and  the  boards  which  receive  the  more  severe  thrusts  in 
service  to  be  supported  to  some  extent  along  their  edges  by 
the  adjoining  boards. 

An  excellent  matched  joint  (Linderman)  for  box  work  is 
shown  in  figure  3,  Plate  XV.  The  taper  lengthwise  in  this 
joint  produces  a  wedging  action  between  the  parts  and  binds 
the  two  pieces  tightly  together  when  they  are  forced  into 
proper  position.  As  the  two  pieces  are  forced  together,  glue 
is  applied  to  the  uniting  surfaces,  which,  if  the  gluing  is 
properly  done,  increases  the  strength  of  the  joint  and  enables 
the  combined  parts  to  approximate  a  single  piece  in  char- 


BOX   DESIGN  45 

acter;  it  is  less  effective  in  material  J/£  inch  or  less  in  thick- 
ness. 

In  constructing  boxes  such  as  Styles  1  and  6,  Plate  III, 
and  those  in. figures  1  and  2,  Plate  IV,  joints  in  the  sides  and 
ends  should  be  so  located  that  there  is  considerable  distance 
between  their  respective  planes,  to  avoid  a  line  of  weakness 
around  the  box. 

An  important  advantage  of  all  matched  joints  is  that  a 
tight  box  is  maintained  even  though  some  shrinkage  occurs. 

Corrugated  Fasteners — In  figure  2,  Plate  XV,  several 
types  of  fasteners  are  shown.  The  fasteners  with  parallel  cor- 
rugations may  also  be  obtained  in  continuous  coils  (figure  4. 
Plate  XV)  for  use  on  automatic  driving  machines  which  cut 
and  drive  the  fasteners  in  one  operation. 

These  fasteners  may  be  used  for  holding,  pieces  together 
and  preventing  relative  endwise  movement  in  the  joints 
(figures  1,  5,  and  6,  Plate  XV)  and  for  preventing  relative  end- 
wise movement  of  pieces  in  Linderman  joints  when  poorly 
glued  (figure  3,  Plate  XV).  They  are  also  driven  across  splits 
and  large  checks  to  prevent  further  development  of  such 
defects ;  greater  efficiency  is  obtained  in  such  cases  if  the 
fasteners  are  driven  from  both  sides. 

The  depth  of  the  fasteners  should  be  slightly  less  than 
the  thickness  of  the  pieces  into  which  they  are  driven  so  that 
the  cutting  edge  may  not  protrude  after  driving.  The  fasten- 
ers with  divergent  corrugations  have  a  tendency  to  draw  the 
pieces  closer  together  when  they  are  driven. 

Physical  Properties  of  Wood — The  physical  properties  of 
wood  have  a  vital  influence  on  the  strength  of  a  box.  The 
effect  of  using  material  the  density  of  which  is  much  lower 
than  the  average  for  the  species  is  to  produce  a  box  in  which 
the  low  density  parts  of  it  are  weak  and  will  usually  break 
quickly  in  service. 

Material  of  low  bending  resistance  is  not  suitable  for  long 
boxes  in  which  the  contents  are  of  such  a  nature  that  con- 
siderable stiffness  in  the  material  is  required  to  maintain  the 
shape  of  the  box. 

Increased  resistance  to  splitting1  is  desirable,  especially 
for  ends  which  are  not  cleated  or  otherwise  reinforced.  If 
some  method  of  reinforcing  against  splitting  must  be  used, 
the  cost  of  the  box  is  increased  unless  the  extra  charges  are 

1See  also  nailing  qualities  of  wood,  page  51 


46  WOODEN  BOX  AND    CRATE   CONSTRUCTION 

balanced  by  a  reduction   in   the  thickness  of  material   made 
possible  by  such  reinforcement. 

Failures  by  puncturing  are  infrequent.  Inspectors  at  the 
ports  of  embarkation  during  war  shipments  estimated  that  less 
than  one  per  cent  of  boxes  inspected  showed  damage  due  to 
puncturing.  The  damage  due  to  this  cause  when  thin  mate- 


Nailed  and  tested  at  once  at  15%  moisture.  100% 

mmmmmaeammmmmmmmmmmm^mmmmmi^i^mmiimmm     90% 


Nailed  and  tested  at  once  at  30%  moisture. 


••^••••••••BI^^MHI^HHl^Ml     75% 

Nailed  at  15%,  tested  at  5%  moisture,  4  months  storage. 


mmmmmmmmmmm^ammmmmm    50% 

Nailed  and  tested  at  once  at  5%  moisture. 

Nailed  at  30%,  tested  at  5%  moisture.  One  year  in  storage. 

•••     10% 

Nailed  at  5%,   tested  at  35%  moisture.     Stored  2  weeks   in   exhaust 
steam. 

^m   10% 

Nailed  at  5%,  dried  to  4^%,  tested  at  35%  moisture.     Two  weeks  dry 
storage,  2  weeks  in  steam. 

Nailed  at  5%,  steamed  to  35%,  tested  at  4,T/2%  moisture.     Two  weekr 
in  steam,  2  weeks  dry  storage. 

Most  .perfect  boxes  nailed  from  shocks  at  15%  moisture. 
Boxes   nailed   at   15%   and   tested   at   once,   taken   as   a   base. 


FIG.  12 — Effect  of  condition  and  change  of  condition  of  lumber  on  strength 

of  boxes   in   storage.     Boxes   for  2  doz.   No.   3  cans,   nailed   with 

seven  cement-coated  nails  to  each  nailing  edge.    Chart  based 

on   tests   to   date.     Data    insufficient    for   accurate 

comparisons. 

rial  must  be  used  can  be  reduced  by  substituting  plywood  for 
veneer,  since  it  offers  more  resistance  to  puncturing.  If 
warped  lumber  or  veneer  is  used,  initial  stresses  are  produced 


BOX    DESIGN  47 

when  such  material  is  forced  to  assume  the  proper  shape  in 
assembling  the  box.  Such  initial  stresses  decrease  the  amount 
of  strength  remaining  for  resisting  the  hazards  of  service. 
Boxes  made  of  such  material  may  also  be  somewhat  mis- 
shapen. 

Moisture  Content1 — The  moisture  content  of  the  material 
used  in  constructing  boxes  influences  their  strength  greatly, 
and  in  various  ways.  An  abnormal  amount  of  moisture  in 
box  material  causes  the  points  of  the  nails  to  pull  more  easily 
from  the  wood,  the  heads  to  pull  through  the  wood,  and  the 
shanks  of  the  nails  to  shear  out  at  the  ends  of  the  boards. 
When  boxes  made  of  green  or  wet  material  subsequently  dry 
out,  the  nails  become  loose  and  pull  easily.  The  boards  also 
split  and  check  because  the  nails  resist  the  shrinkage,  which 
is  the  normal  result  of  drying.  Variations  and  changes  in  the 


FIG.  13 — Effect  of  shrinkage  on  strapped  boxes.     Boxes  made  and  strapped 

at  a  30  per  cent  moisture  content ;  the  boxes  were  photographed 

after  drying  out  to   10  per  cent  moisture  content. 

amounts  of  moisture  contained  in  box  lumber  affect  the 
strength  of  a  box,  as  indicated  by  the  results  of  tests  given 
in  figure  12. 

The  moisture  content  of  box  material  has  a  very  great 
influence  on  the  maintenance  of  the  strengthening  effect  of 
strapping  and  wire  bands.  If  shrinkage  occurs  after  strapping 
is  nailed  on,  the  strapping  buckles  between  the  nails.  (See 
figure  13.)  Straps  with  ends  joined  by  some  sealing  or 


JSee  page   15   for  general   discussion   of   moisture  content. 


48  WOODEN  BOX  AND   CRATE   CONSTRUCTION 

clamping  device  often  become  so  loose  through  shrinkage  of 
the  wood  that  unless  nailed  in  place  they  will  easily  slip  off 
the  box.  Inspectors  have  reported  that  large  quantities  of 
straps  which  have  slipped  off  boxes,  with  the  seals  unbroken, 
are  at  times  left  in  freight  cars  after  unloading.  A  similar 
loosening  effect  may  occur  when  boxes  are  stored  for  a  con- 
siderable time.  The  effect  of  shrinkage  on  the  usefulness  of 
wire  bands  is  similar  to  that  on  strapping. 

It  is  apparent  that  when  straps  or  wire  ties  are  to  be 
used,  the  box  material  should  have  such  a  percentage  of 
moisture  as  it  is  likely  to  retain  after  construction  and  pack- 
ing is  completed ;  this  is  usually  between  12  and  18  per  cent. 
Strapping  should,  if  possible,  be  put  on  boxes  under  maximum 
tension  immediately  prior  to  shipment,  as  the  bad  buckling 
and  loosening  effects  from  shrinkage  in  storage  are  not  then 
so  apt  to  occur. 


I — ^— 


T     •»!    L 

VOL.  2 

I 

VOL.  3 

ih  «• 

VOL.  3 

VOL.  3 

I  .ft  r 

VOL.  1 

I 

£Tt 

L  =  15  FT. 

—  J« 

II 

I 

A_L  

J 

1 

FIG.  14 — Division  of  a  beam  into  volumes  for  describing  the  location  of 

knots. 

Defects1 — Boxes  are  ordinarily  made  of  low-grade  lum- 
ber containing  various  defects.  Such  defects  as  do  not  affect 
the  serviceability  of  the  box  should  be  allowed  to  remain,  in 
order  that  the  amount  of  waste,  and  consequently  the  actual 
cost  of  material,  may  be  the  minimum. 

Larger  knots  may  be  permitted  in  wide  pieces  than  in 
narrow  widths,  but  knots  should  not  be  permitted  to  interfere 
with  proper  nailing.  A  knot  hole,  besides  being  weakening, 
may  cause  loss  of  the  contents  of  a  box.  Knots  are  most 
weakening  in  that  part  of  a  beam  indicated  by  volume  1  in 
figure  14,  next  if  located  in  volume  2,  and  least  weakening  if 
on  any  part  of  volume  3.  Figure  15  shows  a  crate  slat  which 
failed  on  account  of  too  large  a  knot  at  A. 

Knots  should  be  limited  as  to  size,  because  the  weakening 
effect  is  practically  proportional  to  their  effective  diameter, 
measured  as  shown  in  Plate  I.  A  satisfactory  method  of  lim- 


JSee  pages  8  to  10  for  description  of  various  defects. 


BOX    DESIGN 


49 


50 


WOODEN  BOX   AND    CRATE   CONSTRUCTION 


iting  the  size  is  to  require  that  the  effective  diameter  shall  not 
exceed  a  certain  fraction  of  the  width  of  the  board. 

Shakes  and  checks  are  objectionable  in  material  for  boxes 
for  certain  commodities.     They  may  develop  into  splits  and 


TABLE  10. 


HOLDING  POWER  OF  NAILS  IN  SIDE  AND  END  GRAIN  OF 
VARIOUS  SPECIES 


7d  Cement-coated  nails  driven   to  a  depth  of   one   inch  and  pulled 

immediately 


Species 


Per  cent  of 
moisture 


Specific 
gravity 


Withdrawing  pull 
in  Ibs. 


End  grain     Side  grain 


Group  I1 

Pine,  white 7.7 

Pine,  Norway 7.4 

Pine,  jack .  .  7.6 

Aspen 6.5 

Spruce,  red .  10.7 

Spruce,  white ' .  .  7.6 

Pine,  Western  yellow 7.2 

Cottonwood 6.8 

Basswood 6.5 

Fir,  white 7.6 

Cedar 9.3 

Group  II 

Hemlock 8.6 

Pine,  Southern  loblolly  yellow  .  7.7 

Longleaf 8.2 

Group  III 

Elm,  white 8.2 

Gum,  heartwood 6.0 

Gum,  sapwood 8.1 

Sycamore 7.0 

Maple,  silver 6.8 

Group  IV 

Maple 9.3 

Ash,  white 8.9 

Beech 8.4 

Oak,  cow 4.3 

Oak,  post 7.3 

Oak,  red 7.6 

Oak,  white 7.3 

Birch  .  .  8.6 


.391 
.507 
.429 
.412 
.413 
.396 
.433 
.343 
.412 
.437 
.315 


.501 
.516 
.599 


.537 
.48& 
.433 
.552 
.506 


.643 
.640 
.669 
.756 
.732 
.660 
.696 
.661 


122 
149 
145 
141 
133 
131 

96 
129 
124 
101 

93 


139 
142 
196 


212 
179 
189 
243 
252 


350 
347 
322 

277 
351 
297 
268 
298 


203 
254 
245 
186 
199 
196 
196 
177 
175 
183 
144 


236 
268 
313 


305 
243 
220 
314 
304 


406 
407 
414 
323 
345 
333 
289 
406 


cracks  and  thus  increase  the  liability  of  the  box  to  fail  in 
service.  A  board  containing  large  checks  or  shakes  which 
extend  through  from  one  face  to  the  other  should  be  consid- 
ered as  two  boards.  One  method  of  preventing  splits,  checks, 
or  shakes  from  increasing  in  size  is  to  drive  corrugated  fas- 


*Data  are  not  available  on  all  woods  in  each  group. 


BOX    DESIGN  51 

teners  across  the  apparent  line  of  development.  These  corru- 
gated fasteners  should  be  driven  only  when  the  board  can  be 
firmly  supported  opposite  the  point  of  driving,  as  otherwise 
the  attempted  remedy  may  prove  to  be  detrimental. 

Cross  grain,  a  slope  of  the  fibers  with  respect  to  the  main 
axis  of  a  stick,  is  one  of  the  most  serious  defects  affecting  the 
strength  of  box  and  crate  material  because  it  is  very  common 
and  not  easily  detected. 

Cross  grain  in  box  lumber  is  detrimental  because  it  in- 
creases the  danger  of  failure  in  boards  which  are  subjected  to 
bending  and  puncturing  stresses ;  also  because  it  makes  the 
wood  more  susceptible  to  splitting  when  nails  are  driven  where 
the  defect  occurs. 

Insect  holes,  if  large  and  present  in  sufficient  numbers, 
frequently  impair  the  strength  of  box  lumber.  They  also 
affect  the  appearance  and  tightness  of  boxes,  but  in  some 
cases  such  material  can  be  used  with  a  resulting  saving  in  cost. 

Rot  is  often  found  in  low  grades  of  lumber ;  the  extent  to 
which  it  may  be  permitted  in  box  and  crate  material  depends 
on  the  purpose  for  which  the  container  is  intended.  Rot 
should  not  be  allowed  in  pieces  subjected  to  great  stresses, 
or  wherever  nails  are  driven.  The  slat  C  at  the  bottom  of 
the  crate  in  figure  15  broke  because  it  wras  partly  decayed. 

Occasional  worm  holes  in  wood  do  not  seriously  weaken 
it,  but  pieces  which  are  badly  perforated  should  not  be  used 
where  strength  or  nail-holding  power  is  essential.  As  a  rule, 
worm  holes  indicate  decay  in  the  material  in  which  they 
occur. 

Nailing  Qualities  of  Wood — The  nailing  qualities  of  the 
wood  are  of  vital  importance  in  box  construction.  It  is  waste- 
ful practice  to  make  a  nailed  box  of  lumber  of  considerable 
strength  unless  the  parts  are  nailed  together  in  such  a  way 
as  to  balance  the  construction. 

The  serviceability1  of  a  nailed  joint  varies  with  the  dens- 
ity of  the  wood,  the  ease  with  which  it  is  split  and  sheared 
by  nails,  the  initial  moisture  content,  changes  in  moisture 
content2,  the  character  and  location  of  defects,  and  the  direc- 
tion of  the  nails  relative  to  the  grain  of  the  wood. 

It  will  be  observed  from  the  preceding  table  that,  in  gen- 
eral, the  difference  between  the  resistances  of  the  nails  to 


1See  page  53  for  the  effect  of  nails  on  the  strength  of  a  joint. 
2See  page  15,  moisture  content. 


52 


WOODEN   BOX  AND  ^CRATE   CONSTRUCTION 


Load  in   Pounds   Required  to   Pull  One   Nail 


BOX    DESIGN  53 

pulling  from  the  end  grain  and  from  the  side  grain  is  greater 
for  the  light  soft  wood  than  for  the  heavier  dense  ones. 

At  times  it  is  necessary  to  use  denser  woods  for  the  cleats 
or  ends  or  both  than  are  used  for  the  other  parts  of  the  box 
in  order  to  secure  sufficient  nail-holding  power  to  balance  the 
construction. 

Some  woods  are  very  susceptible  to  nail  splitting;  also 
nails  easily  shear  out  at  the  ends  of  the  boards  of  some  spe- 
cies. Both  of  these  difficulties  increase  the  probability  of  the 
ends  being  pulled  away  from  sides,  top,  and  bottom  of  the 
box.  Nails  driven  in  checks,  rot,  etc.,  have  little  holding 
power.  The  holding  power  of  nails  changes  with  the  lapse 
of  time  after  driving,  as  shown  in  figure  16. 

Tests  on  the  holding  power  of  nails  driven  parallel  with 
and  at  an  angle  to  the  grain,  as  shown  in  figure  3,  Plate 
VII,  show  no  appreciable  difference  in  holding  power  when 
pulled  immediately.  In  these  tests  the  direction  of  pull  was 
perpendicular  to  the  surface  of  the  board.  Nails  were  sim- 
ilarly driven  in  green  pine,  which  was  then  dried  thoroughly 
in  an  oven  at  a  temperature  of  100°  C,  before  testing;  and  it 
was  found  that  while  the  diagonally-nailed  pieces  started  to 
fail  at  lower  loads  than  the  straight  nailed,  the  diagonally- 
nailed  pieces  soon  developed  more  strength  with  the  result 
that  the  force  required  to  withdraw  the  nails  was  considerably 
higher  than  for  those  with  straight  nailing.  These  tests  in- 
dicate that  diagonal  nailing  may  be  of  some  advantage  if 
boxes  are  to  remain  in  storage  where  the  moisture  content 
will  be  reduced. 

Fastenings  and  Reinforcements — Nails  are  the  most  com- 
mon fastenings  for  box  materials.  The  serviceability  of  a 
nailed  joint  varies  with  different  nail  characteristics  and  de- 
tails of  nailing,  such  as  the  character  of  the  shank  surface,  the 
length  and  diameter  of  the  shank,  the  flexibility  of  the  shank, 
the  size  of  the  head,  and  the  number  or  spacing  of  the  nails. 
A  special  type  of  nails  known  as  box  nails1  is  made  for  use 
in  the  box  industry.  In  order  to  minimize  the  splitting  of 
material  these  nails  are  made  of  smaller  wire  than  the  ordinary 
plain  wire  nails  used  in  building  construction,  though  they 
must  be  of  sufficient  diameter  not  to  bend  or  kink  in  driving. 
Another  advantage  of  slender  nails  is  that  they  are  not  so 
readily  loosened  in  the  wood  as  those  of  larger  diameter  and 
equal  length,  because  the  slender  nails  bend  more  readily  un- 


pages  139-140  for  table  of  sizes  of  sails,  etc. 


54 


WOODEN  BOX   AND   CRATE   CONSTRUCTION 


of  End 
NAIL/NG    DETA/LS 


Corner 
NAILING  DETA/LS    FO#    STYLE- 2- 6OXES 


orner  of  Sx*o 
3TYL£-2+~OOXES 


Cor  nor  of  End  Corner 

NAILING   DETAILS   r~OR    STYLES-BOXES 


C  ornmr  of  S&9 


NA/LING    D£TA/LS     FVK    STYLES-BOXES 


NOTES 

For  all  styles  when  the  end  and  cleats  are 
%  inch  or  less,  d  —  %  inch.  For  all  thicker 
stock,  d  —  %  inch. 

When  w  rr  2  inches  or  less,  r  —  %  inch. 
For  larger  values  of  w,  r  —  %  inch. 

In  style- 1,  L  —  length  of  nails  holding  sides. 

In  style- 2%,  n  —  %  to   %  of  an  inch. 

Nails  thru  cleats  and  ends  should  be  long 
enough  to  clinch  well,  aJid  spaced  approxi- 
mately the  same  as  in  the  adjacent  side,  top 
or  bottom  as  shown. 

Good  construction  is  obtained  with  6d  nails 
by  making  s  —  1%  inches  for  sides  and  s  —  2 
inches  for  tops  and  bottoms.  With  larger  nails 
s  may  be  increased  %  inch  for  each  penny  in 
excess  of  six.  These  values  of  s  may  be  varied 
enough  to  allow  an  odd  number  of  nails  to  be 
used  in  edges  where  the  nails  are  staggered  in 
two  rows,  also  to  prevent  nails  being  driven  in 
cracks,  and  to  give  additionaJ  nails  when  con- 
ditions demand.  Every  board  shall  have  at 
least  two  nails  in  each  nailing  edge. 


FIG.  17 — Details  for  nailing  standard  styles  of  boxes  for  domestic  shipment. 


BOX    DESIGN  55 

der  the  shocks  of  rough  handling  and  the  weaving  strains  that 
a  box  receives  in  transportation  and  are  not  worked  back 
and  forth  their  full  length.  If  nails  are  too  slim,  however,  the 
excessive  bending,  which  readily  occurs,  will  frequently  cause 
them  to  break  between  the  parts  which  they  unite.  Box 
nails  may  be  obtained  cement-coated,  or  with  plain  or  barbed 
shanks.  The  cement  coating  increases  the  friction  between 
the  shank  of  the  nail  and  the  wood.  Barbed  nails  are  so 
called  because  the  shanks  of  the  nails  have  on  their  surfaces 
a  series  of  small  barbs  or  teeth. 

The  holding  power  of  nails  of  the  same  kind  but  of  dif- 
ferent sizes  against  withdrawal  in  line  with  the  shank  is  for 
ordinary  sizes  approximately  proportional  to  the  amount  of 
shank  surface  in  contact  with  the  wood.  If  more  holding 
power  is  needed,  it  is  preferable  to  increase  the  number  or 
length  of  the  nails  rather  than  their  diameter.  In  this  way 
the  advantages  of  slim  nails  are  retained,  and  the  additional 
shank  surface  is  secured  with  less  additional  metal  in  the  nails. 

The  size  and  spacing  of  nails  should  be  such  as  will  not 
cause  an  unreasonable  number  of  failures  because  of  splitting 
the  material  in  driving. 

One  of  the  difficult  problems  in  a  nailed  box  is  to 'Secure 
sufficient  nail-holding  power  to  stress  all  the  wooden  parts  of 
a  box  to  their  maximum,  and  still  maintain  balanced  construc- 
tion. In  some  species  of  wood  a  large  number  of  small  nails 
may  be  required,  and  in  others  a  smaller  number  of  larger 
nails  may  be  necessary  to  secure  the  desired  results.  Box 
woods  are  divided  into  four  groups  according  to  their  nailing 
qualities.1.  The  nailing  schedule  on  page  102  gives  informa- 
tion for  proper  nailing  of  boxes  constructed  of  woods  from 
these  groups. 

Directions  for  Nailing — General  directions  and  details 
for  nailing  cleats,  sides,  top,  and  bottom  to  ends  of  several 
styles  of  boxes  for  domestic  shipment  are  given  on  page  103. 
(See  also  figure  17.)  For  foreign  shipment  the  spacing  should 
be  about  one-half  inch  less  than  given  on  page  102. 

In  figure  18  are  shown  the  relative  amounts  of  rough 
handling  required  to  cause  loss  of  contents  in  boxes  con- 
structed with  various  spacing  of  nails.  A  box  with  seven 
nails  per  nailing  edge  is  taken  as  the  basis  for  comparison. 

The  size  and  spacing  of  nails  in  some  instances  depends 
largely  on  the  properties  of  the  material  upon  which  the  heads 


page  100  for  grouping  of  species. 


56  WOODEN  BOX   AND    CRATE   CONSTRUCTION 

of  the  nails  rest.     If  this  material  is  of  low  density  and  easily 
sheared  by  the  nails,  it  is  advisable  to  have  them  closer  to- 


8  nails  per  nailing  edge. 

MMI«RinB^HHHHBi^HHHHBI     100% 
7  nails  per  nailing  edge. 

•^••••i^HHBHHHH    75% 


145% 


6  nails  per  nailing  edge. 

rnmn^m  22% 

5  nails  per  nailing  edge. 

A  box  with  seven  nails  per  nailing  edge  taken  as  a  base. 


FIG.  18 — Relation  of  number  of  nails  to  amount  of  rough  handling  required 
to  cause  loss  of  contents.     Nailed  boxes  for  2  doz.  No.  3  cans. 

gether  than  would  be  required  with  a  denser  wood  offering 
more  resistance  to  such  shearing  action. 

Placing  nails  closer  together  gives  more  holding  power 
per  inch  of  nailing  edge  for  the  wood  in  which  the  points  are 
held,  unless  the  nails  become  so  close  that  their  holding  power 
is  reduced  by  the  splitting  of  the  wood. 

Side  Nailing — The  term  "side  nailing"  refers  to  the  nail- 
ing of  the  top  and  bottom  to  the  edges  of  the  sides.  If  the 
boards  are  less  than  T7y  inch  in  thickness,  such  nailing  will 
add  little  to  the  serviceability1  of  the  box  but  will  make  a 
tighter  box,  provided  the  strains  due  to  the  contents  and  the 
hazards  encountered  are  not  severe  enough  to  spring  the 
boards  and  produce  nail  splitting  at  these  edges.  The  size 
of  nails  should  be  as  shown  by  the  nailing  schedule  on  page 
102.  Six  penny  nails  and  smaller  should  be  spaced  approxi- 
mately six  inches  apart,  and  this  distance  increased  one  inch 
for  each  penny  over  six. 

Nails  for  Clinching — The  character  of  the  surface  of  the 
shank  is  relatively  unimportant  in  nails  to  be  clinched, 
the  head  and  the  clinched  end  being  the  important  factors. 
Slender  nails  are  to  be  preferred  because  they  lessen  the  dan- 
ger of  splitting  the  wood  and  clinch  more  easily.  The  use  of 
cleating  nails  made  with  a  "side  point"  is  increasing.  The 
long  slender  point  turns  back  into  the  wood  when  driven  and 
gives  more  uniform  results  than  right-angled  clinching. 


1See  discussion   of  strapping,   page   60. 


BOX    DESIGN 


57 


Large  Nail  Heads1 — Tests  have  demonstrated  that  large 
nail  heads  have  considerable  advantage  over  small  ones  be- 


FIG.   19 — Injury  to  wood  fiber  resulting  from  overdriving  nails. 


cause  of  the  additional  resistance  offered  to  being  pulled  di- 
rectly through  the  wood.  Large  heads  also  prevent  the  shanks 
of  the  nails  from  shearing  out  as  easily  at  the  ends  of  the 

TABLE  11.    EFFECT  OF  SIZE  OF  HEADS  ON  STRENGTH  OF  A  NAILED  JOINT 


T  _  • 

01  

Size  of 

Diameter 

Load 

Heads 

Nails 

Load 

Heads 

Nails 

Material 

nail 

of  heads 

per  nail 

off 

broken 

per  nail 

off 

broken 

inches 

pounds 

%  total 

%  total 

pounds 

%  total 

%  total 

6d 

.36 

312 

0 

0 

186 

0 

0 

6d 

.26 

257 

0 

0 

155 

0 

0 

6d 

.24 

250 

0 

0 

154 

0 

0 

5/16-inch  red  gum 

5d 

.28 

213 

100 

0 

158 

33 

16 

rotary  cut  

5d 

.22 

196 

22 

0 

152 

8 

:  8 

5d 

.19 

212 

0 

0 

164 

0 

0 

4d 

.28 

239 

83 

0 

173 

67 

16 

4d 

.22 

248 

100 

0 

168 

33 

0 

1 

4d 

.19 

222 

0 

0 

163 

0 

0 

6d 

.36 

220 

11 

0 

164 

0 

0 

6d 

.26 

194 

0 

0 

139 

0 

0 

6d 

.24 

181 

0 

0 

139 

0 

0 

3/8-inch  sawed 

5d 

.28 

178 

33 

0 

138 

33 

17 

white  pine  

5d 

.22 

149 

0 

0 

142 

8 

8 

5d 

.19 

122 

0 

0 

134 

0 

0 

4d 

.28 

154 

22 

0 

172 

33 

67 

4d 

.22 

146 

0 

0 

161 

11 

22 

4d 

.19 

116 

0 

0 

150 

0 

0 

boards  when  thin  material  is  used.  In  many  nails  with  extra 
large  heads  the  material  where  the  shank  joins  the  head  is  so 
thin  that  failures  frequently  occur  in  the  nail  at  this  point, 
thus  preventing  to  a  large  extent  any  addition  to  the  strength 
of  the  box.  Large  headed  nails  are  advantageous  for  mate- 

1See  page  139  Appendix  for  table  of  size  and  thickness  of  heads. 


58 


WOODEN  BOX   AND    CRATE   CONSTRUCTION 


rial  which  contains  many  checks  or  which  splits  easily  and 
for  thin  and  low-density  material ;  in  fact,  when  thin  material 
is  being  nailed  the  size  of  the  head  and  the  length  of  the  nail 
are  of  nearly  equal  importance,  with  the  necessity  for  large 


Amount   overdriven    in    one-sixteenth-inch    units 
FIG.  20. — Effect  of  overdriving  nails 

heads  increasing  as  the  thickness  of  the  material  is  reduced. 

In  Table  11  are  shown  results  on  approximately  100  nails 
with  various  sizes  of  heads.  The  small  heads  are  the  stand- 
ard sizes  for  the  different  nails.  It  is  shown  that  a  very  large 
percentage  of  the  heads  pulled  from  the  four  or  five  penny 
nails. 

Overdriving  Nails — One  of  the  serious  faults  in  nailing 
boxes  is  overdriving.  Nails  should  be  driven  until  the  top  of 
the  head  is  just  flush  with  the  surface  of  the  material.  Over- 
driving crushes  and  injures  the  wood  fibers  (figure  19)  and 
decreases  the  strength  to  an  extent  which  depends  on  the 


BOX    DESIGN 


59 


amount  of  overdriving  (figure  20).  On  the  other  hand,  if  the 
heads  of  the  nails  are  not  driven  flush  with  the  surface,  the 
joint  between  the  boards  is  not  so  tight  and  rigid  as  it  would 
be  otherwise,  also  there  is  danger  of  the  nail  heads  catching 
on  objects,  especially  strapping  on  other  boxes. 

Screws — Screws  are  an  admirable  fastening  when  properly 
driven.  They  permit  a  box  to  be  easily  opened  without  dan- 
ger of  injury  to  box  or  contents  from  bars,  chisels,  or  other 
tools.  Boxes  made  with  screws  are  also  easily  closed  again 
for  reshipping,  which  feature  may  be  objectionable  with  ref- 
erence to  theft  of  goods  in  transit.  Some  method  of  sealing 
boxes  which  are  closed  with  screws  may  be  used  to  lessen  the 
thieving  losses.  Other  objections  to  screws  are  their  cost, 
the  cost  of  proper  driving,  and  the  great  tendency  to  drive 
screws  improperly  their  full  length  with  a  hammer,  thereby 
sacrificing  much  of  the  strength  that  they  should  give. 

The  data1  in  Table  12  show  the  effect  of  different  methods 
of  driving  on  the  holding  power  of  No.  12  screws. 

TABLE  12.    RESISTANCE  TO  WITHDRAWAL  OF   No.   12   SCREWS 

Screws  1^4  inches  long,  driven  to  one  inch  depth  in  holes  ^-inch  in 
diameter. 


Kind  of  wood 

Method  of  driving 

Screw  driver 

Ham 

merz 

Pounds 

Per  cent 

Pounds 

Per  cent 

Basswood 

478 
1144 
687 
841 

100 
100 
100 
100 

281 
681 
403 
570 

59 
60 
59 

68 

Yellow  pine 

Red  gum 

Birch  

Staples — Staples  are  used  for  fastening  both  wire  bands3 
and  flat  metal  straps  in  place.  To  secure  good  holding  power 
they  should  be  driven  for  a  considerable  distance  into  solid 
wood  and  if  driven  into  thin  material  the  points  should  be 
clinched. 

In  holding  box-strapping  in  place,  staples  have  an  ad- 
vantage because  they  do  not  weaken  it  by  puncturing  as  nails 
do,  and  they  also  hold  the  edges  of  a  strap  down  together  and 
present  a  curved  part  to  strike  against  the  edges  of  straps  on 
another  box,  thus  lessening  the  danger  of  catching  and  tear- 
ing them  off. 

1See   page   63    for   information    on    cleats    fastened   with    nails,    wood   screws,    and 
drive  screws. 

JOne  final  turn  with  screw  driver. 

"See  discussion  of  wirebound  boxes  on  page  67. 


60  WOODEN  BOX  AND   CRATE   CONSTRUCTION 

Staples  will  not,  as  nails  do,  hold  the  tension  in  strap- 
ping, and  therefore  some  method  must  be  used  of  accomplish- 
ing this  by  sealing  or  fastening  the  ends  together. 

Strapping  and  Wire  Bindings — The  use  of  metal  bindings 
around  boxes  may  serve  one  or  more  of  the  following  pur- 
poses: 

1.  To   reinforce   the    package   and    increase    its    service- 
ability. 

2.  To  minimize  pilfering. 

3.  To  secure  lighter,  yet  equally   serviceable  packages 
Types  of  Metal  Bindings 

r__  f  Annealed 

,,.,,..    ..  F        Straps"   Unannealed 

Metal  bindings.  .  .4  I    . 

Wires {Single  wire 

[  [Two  or  more  wires  twisted 

Two  types  of  metal  binding  are  in  common  use,  viz. : 
flat  straps  and  wires. 

Flat  straps  are  either  annealed  or  unannealed.  The  dif- 
ferences in  the  properties  of  these  two  kinds  of  metal  strap- 
ping result  from  a  special  heat  treatment  given  unannealed 
strapping,  thus  producing  annealed  strapping. 

Annealed  strapping,  as  a  result  of  this  treatment,  has  a 
much  lower  tensile  strength,  stretches  considerably  more  be- 
fore failure  or  under  a  given  load  than  unannealed  strapping 
of  the  same  size  and  is  also  more  easily  penetrated  by  nails. 
There  are  many  special  types  of  annealed  strapping  such  as 
the  plain,  embossed,  and  corrugated,  as  well  as  various  other 
types,  that  have  holes  or  slots  cut  to  receive  the  nails. 

Wire  ordinarily  used  for  box  construction  is  annealed. 
It  is  used  either  as  a  single  strand,  ordinarily  held  in  place 
by  twisting  the  ends,  or  in  two  or  more  strands  twisted  to- 
gether .and  held  in  place  by  nails  driven  through  spaces  be- 
tween the  wires. 

Plain  unannealed  strapping  is  generally  applied  by  fas- 
tening the  overlapping  ends  with  a  seal.  The  seal  should 
provide  a  joint  whose  strength  is  nearly  equal  to  that  of  the 
strap. 

Straps  nailed  around  the  extreme  ends  act  somewhat  as 
a  cleat  in  resisting  skewing  or  weaving  of  the  box;  retard  the 
nails  pulling  from  the  ends ;  prevent  the  nails  in  the  straps 
from  pulling  the  heads  through  the  sides,  top,  and  bottom ; 
and  assist  in  preventing  the  nails  from  shearing  out  at  the 
ends  of  the  boards  by  acting  in  the  nature  of  washers  under 
the  nail  heads.  This  method  of  reinforcement  also  gives  more 


BOX    DESIGN  61 

secure  nailing  because  the  nails  driven  through  the  straps  are 
in  addition  to  those  ordinarily  used  in  the  manufacture  of  the 
box.  The  strapping  should  be  held  in  place  with  nails  of  the 
same  size  as  those  used  to  hold  the  sides,  top,  and  bottom  to 
the  ends. 

Nailless  straps  placed  some  distance  from  the  ends  of  a 
box  absorb  considerable  shock  which  is  ordinarily  trans- 
mitted to  the  sides,  top,  and  bottom,  and  thus  relieve  the 
direct  pull  on  the  nails  in  the  end  and  also  reduce  failures  due 
to  the  sides,  top,  and  bottom  splitting  or  breaking  across  the 
grain.  Nailless  straps  do  not  add  as  much  rigidity  to  a  box 
as  nailed  straps  and  have  less  value  in  reducing  shear  on  the 
nails  in  the  ends  of  the  sides,  top,  and  bottom.  In  some  cases 
nailless  straps  permit  the  use  of  thinner  material  in  the  sides, 
top,  and  bottom  than  is  permitted  by  straps  nailed  around  the 
end  of  the  box. 

Either  annealed  or  unannealed  strapping  may  be  used 
when  nailed  around  the  box,  whereas,  only  unannealed  strap- 
ping should  be  used  when  held  in  place  with  a  seal. 

Metal  bindings,  particularly  the  nailless  variety,  to  be 
most  effective,  should  be  drawn  sufficiently  tight  to  cut  into 
the  corners  of  the  box,  and  maintained  under  considerable 
tension  until  the  box  has  served  the  desired  purpose. 

One  method  of  retaining  the  tension  in  nailless  strapping 
is  by  building  the  box  in  such  a  manner  that  neither  the  top 
nor  bottom  laps  the  sides.  The  tension  of  the  strapping 
when  drawn  snug  is  sufficient  to  spring  the  sides,  top  and 
bottom  of  the  box  in  against  the  contents  so  that  the  edge 
boards  overlap  near  the  center.  As  a  result  the  middle  of  the 
box  is  smaller  than  the  ends,  and  the  straps  will  not  slip  off, 
even  though  the  box  shrinks. 

Another  method  of  applying  straps  between  the  ends  is 
to  put  battens1  on  each  face  as  shown  in  figure  1,  Plate  V, 
and  then  nail  the  straps  to  the  battens.  The  battens  make  it 
possible  to  use  longer  nails  without  injuring  the  contents.  In 
some  instances,  the  straps  may,  in  the  absence  of  such  bat- 
tens, be  nailed  directly  to  faces  of  the  box,  if  the  material 
packed  will  not  be  injured  by  the  nail  points. 

Shipping  containers  are  frequently  subjected  to  adverse 
moisture  conditions  and  for  that  reason  the  metal  bindings 
should  be  treated  to  resist  rust. 

Boxes  having  comparatively  thin  sides,  top,  and  bottom 

7See  page  62  for  discussion  of  battens. 


62  WOODEN  BOX  AND   CRATE   CONSTRUCTION 

and  bound  with  metal  bindings  often  are  more  serviceable 
than  those  constructed  of  heavier  lumber  without  such  bind- 
ings. In  some  cases  it  is  possible  to  reduce  the  thicknesses 
of  material  20  per  cent  or  more  and  at  the  same  time  permit 
.the  use  of  a  poorer  grade  of  lumber  when  metal  bindings  are 
properly  used,  without  any  reduction  in  serviceability  of  the 
container. 

REINFORCEMENTS  AND  HANDLES 

Corner  Irons,  Hinges,  and  Locks — Corner  irons  may  be 
necessary  on  boxes  for  certain  conditions  of  service,  such  as 
returnable  boxes  and  heavy  chests.  The  style  of  iron  to  be 
used  will  depend  entirely  on  the  conditions  of  service. 

The  important  requirements  of  hinges  and  locks  are  that 
they  hold  the  cover  securely  in  place,  do  not  project  so  as  to 
interfere  with  handling  and  stacking,  and  do  not  easily  get 
out  of  usable  condition.  Locks  ordinarily  should  be  of  such 
design  that  they  may  be  held  in  a  closed  position  by  a  seal 
rather  than  a  key.  Hinges  should  allow  the  cover  to  open 
until  the  free  edge  lies  in  a  plane  parallel  to  the  bottom  of  the 
box,  so  as  to  minimize  the  danger  of  breakage,  or  injury  to 
the  box. 

Battens — Battens  and  cleats  are  very  much  alike.  Either 
or  both  are  put  on  some  styles  of  boxes  when  they  are  made, 
or  later  to  give  additional  strength.  They  may  be  on  the  inner 
or  outer  surface  of  a  box.  (See  Plates  III  and  VIII.)  Cleats 
and  battens  on  the  outer  surface  usually  increase  the^  displace- 
ment and  increase  the  cost,  and  often  interfere  with  the  stack- 
ing of  the  boxes.  They  should  be  used,  therefore,  only  when 
no  other  method  of  construction  can  be  devised  which  will 
be  as  economical  and  as  satisfactory. 

Hand-holds  and  Handles — It  is  desirable  to  have  hand- 
holds or  handles  on  many  boxes,  such  as  those  to  contain 
heavy  commodities  which  must  be  handled  with  reasonable 
care,  and  commodities  of  delicate  construction  like  scientific 
instruments.  Returnable  boxes  should  also  have  hand-holds 
or  handles,  as  this  construction  tends  to  encourage  careful 
handling. 

Two  common  types  of  hand-holds  are  shown  in  figures  1 
and  3,  Plate  VI.  Being  near  the  points  of  the  nails  holding 
the  tops  to  the  ends  they  weaken  the  ends  in  such  a  manner 
as  to  increase  the  danger  of  failure  along  the  lines  passing 
through  the  length  of  the  hand-holds. 


BOX    DESIGN  63 

One  method  of  arranging  a  hand-hold  on  boxes  of  Styles 
2,  2]/2,  and  3,  Plate  III,  is  to  shape  the  lower  edge  of  cleats 
5-1  and  6-11  as  shown  by  the  section  in  figure  2,  Plate  VI. 

A  method  of  applying  rope  handles  to  boxes  is  shown  in 
figure  4,  Plate  VI.  Three  methods  of  fastening  the  cleats  to 
the  ends  have  been  used  as  follows:  four  No.  11  flat-head 
wood  screws,  1^4  inches  long,  six  7d  cement-coated  nails 
driven  through  and  clinched,  and  four  No.  11  drive  screws,  1^4 
inches  in  length.  Wood  screws  must  be  properly  driven  with 
a  screw  driver2,  as  driving  with  a  hammer  to  any  appreciable 
depth  seriously  reduces  their  holding  power.  The  cleats  are 
1%  inches  thick  and  the  ends  ^f  inch  thick.  The  rope  is 
three  strand  and  is  Y&  of  an  inch  in  diameter.  Both  types  of 
screws  are  arranged  as  shown  in  figure  4,  Plate  VI.  It  should 
be  noted  that  in  each  case  two  nails  or  screws  pass  through 
that  part  of  the  rope  within  the  vertical  groove  of  the  cleats 
and  the  lowest  of  these  two  screws  or  nails  is  about  2  inches 
from  the  end  of  the  rope.  The  grooves  in  the  cleats  should 
be  of  such  size  that  the  rope  is  squeezed  when  the  screws  or 
nails  are  driven  home.  Tests  consisting  of  a  pull  on  the  rope 
in  a  direction  perpendicular  to  the  box  ends  have  shown  that 
the  nailed  construction  (six  7d  cement-coated  nails  per  cleat) 
offers  the  greatest,  and  the  drive  screw  (four  No.  11  drive 
screws  1^4  inches  long)  the  least  resistance  to  failure,  the 
wood  screws  (four  No.  11  flat-head  wood  screws  1^4  inches 
long)  giving  intermediate  results. 

Webbing  has  been  recommended  as  a  substitute  for  rope 
in  handles.  One  style  is  shown  in  figure  6,  Plate  VI.  The 
end  piece  of  the  box  is  slotted  and  the  webbing  is  passed 
through  these  slots  and  nailed  on  the  inner  surface  of  the  box. 
Several  large-headed  nails  should  be  used  and  may  be  driven 
through  and  clinched.  Handles  of  this  type  have  sustained 
an  average  direct  pull  before  failure  of  800  pounds  in  a  direc- 
tion perpendicular  to  the  end  of  the  box. 

Another  method  of  attaching  webbing  handles  is  shown 
in  figure  5,  Plate  VI,  in  which  the  webbing  is  passed  through 
^-inch  round  holes  and  the  ends  secured  by  nails.  Such 
handles  have  sustained  a  direct  pull  of  700  pounds  perpendic- 
ular to  the  end  of  a  box.  These  handles  are  made  of  seven- 
cord  cotton  rein  webbing  ^  inch  thick  and  1*4  inches  wide. 
One  of  their  advantages  over  rope  handles  is  that  cleats  are 

'See  figures  3  and  4,  Plate-  XIV. 
2See  table  on   page  59. 


64  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

not  needed  to  hold  the  webbing  and,  therefore,  it  is  possible 
to  construct  a  box  with  greater  volumetric  efficiency. 

Many  styles  of  metal  handles  can  be  obtained  from  man- 
ufacturers of  trunk  and  chest  hardware.  One  objection  to 
many  types  of  metal  handles  is  that  in  case  a  box  or  chest 
drops  on  an  end,  the  handle  usually  extends  in  such  a 'position 
as  to  get  the  full  force  of  the  impact,  which  in  many  instances 
crushes  in  the  end  of  the  box  or  breaks  the  handle. 

CHARACTERISTICS  OF  THE  VARIOUS  STYLES  OF  BOXES 

Nailed  Boxes — In  Style  1,  Plate  III,  boxes,  the  grain  of 
the  ends  and  sides  runs  approximately  parallel  to  the  top  and 
bottom  surfaces.  One  of  the  common  failures  in  this  type  of 
box  is  splitting  of  the  ends  and  sides,  or  failure  of  the  joints 
in  these  parts,  since  the  only  resistance  to  such  failures  lies 
in  the  strength  of  joints,1  if  present,  or  the  strength  of  wood 
in  tension  across  the  grain,  which  is  not  large  and  is  extremely 
variable  in  any  species  of  wood.  The  smaller  holding  power 
of  nails  driven  into  the  end  grain  of  wood,  i.  e.,  with  their 
shanks  parallel  with  the  grain,  as  compared  to  side  grain  nail- 
ing is  a  source  of  weakness  in  the  joints  between  sides  and 
ends. 

To  improve  on  Style  1  ends  and  guard  against  the  lia- 
bility of  complete  failure  from  splitting  of  ends  and  sides, 
rectangular  and  sometimes  triangular  corner  cleats  (Style  5) 
are  added  inside  when  the  character  of  the  contents  permits. 
This  construction  does  not  increase  the  displacement  of  the 
box  and  is,  therefore,  not  objectionable  in  that  respect.  If 
these  cleats  can  be  made  large  enough  the  sides  may  also  be 
nailed  to  them,  which  of  course  increases  the  strength  of  the 
nailing  at  this  point.  These  inside  cleats  should  be  shorter 
than  the  inside  depth  of  the  box,  so  that  if  the  sides  and  ends 
shrink2  the  cleats  will  not  cause  an  opening  of  the  joints  be- 
tween the  bottom  and  ends. 

The  most  common  method  of  preventing  box  ends  from 
splitting  and  of  supplementing  the  holding  power  of  nails 
driven  in  the  end  grain  is  the  addition  of  two  outside  cleats 
on  each  end  as  shown  in  Style  4,  Plate  III.  These  cleats 
should  be  long  enough  to  come  nearly  flush  with  the  outer 
surfaces  of  the  top  and  bottom.  They  will  thus  aid  in  keep- 
ing the  top  and  bottom  in  place  and  will  also  take  some  of 

1For   discussion    of   joints   see   page   43. 
2See  page   22. 


BOX    DESIGN  65 

the  thrust  if  a  box  is  dropped  on  a  corner.  If  a  box  is  con- 
structed with  the  ends  of  these  cleats  made  exactly  flush  with 
the  outer  surfaces  of  the  top  and  bottom,  and  shrinkage  occurs 
later,  it  may  cause  the  ends  of  the  cleats  to  project  beyond 
the  top  and  bottom ;  and  they  may  be  pulled  loose  if  the  box 
is  slid  in  such  a  way  that  the  ends  of  the  cleats  catch  on  some 
object.  This  failure  is  more  apt  to.  happen  with  heavy  boxes 
and  with  boxes  that  are  handled  in  chutes  and  slides.  The 
amount  that  the  cleats  should  be  cut  short  to  allow  for  shrink- 
age depends  on  the  moisture  content  of  the  lumber  when  the 
box  is  constructed  and  the  storage  conditions  afterward1. 
Usually  an  allowance  of  from  l/%  to  T%  of  an  inch  at  each 
end  will  be  sufficient. 

The  reason  for  the  two  additional  horizontal  cleats  5-1 
and  5-32  on  Style  2  (Plate  III)  is  to  give  increased  nail-hold- 
ing power  to  the  end  of  the  box.  The  greatest  increase  in 
nail-holding  power  will  be  obtained  when  the  cleats  are  made 
of  the  denser  woods.  The  usual  failure  in  these  ends  is  a 
split  along  the  inner  edge  of  cleats  5-1  or  5-3,  which  allows  a 
cleat  with  part  of  the  end  board  to  pull  away  with  the  top  or 
bottom.  The  resistance  to  such  failure  is  due  to  the  strength 
of  the  end  board  in  tension  supplemented  by  the  action  of  the 
vertical  cleats.  In  Styles  2  and  2%  it  is  possible  to  get  more 
nails  in  the  vertical  cleats  near  the  top  and  bottom  edges  of 
a  box  than  in  Style  3,  which  more  effectually  prevents  the 
box  end  from  splitting  adjacent  to  the  edge  of  the  horizontal 
cleats. 

The  vertical  cleats  in  Styles  2  and  2^2  should  also  be  cut 
slightly  short,  so  that  if  shrinkage  occurs  in  the  end  pieces 
these  cleats  will  not  hold  the  top  and  bottom  and  allow  the 
end  boards  to  pull  away.  Style  2^?  also  has  the  advantage 
that  when  the  bottom  and  top  are  being  nailed  to  the  ends  the 
notches  or  steps  on  the  vertical  cleats  take  the  thrust  that 
would  otherwise  come  on  the  nails  holding  the  horizontal 
cleats.  In  some  cases,  as  when  driving  several  nails  into  a 
cleat  made  of  dense  wood,  this  thrust  is  very  severe. 

In  manufacturing  boxes  with  square  ends  Style  3  has  the 
advantage  that  all  four  cleats  are  the  same  length,  hence  in- 
terchangeable. When  a  very  symmetrical  end  is  desired  rather 
than  the  strongest  end  the  mitred  cleats  are  preferred. 

Inasmuch  as  one  of  the  chief  functions  of  cleats  in  many 


aSee  page  22. 

-See  figures  3  and  4,  Plate  XIV. 


66  WOODEN  BOX  AND    CRATE   CONSTRUCTION 

boxes  is  to  provide  additional  nail-holding  power  in  the  box 
ends,  it  is  desirable  that  the  cleats  and  end  boards  be  the 
same  thickness,  so  that  the  same  sized  nails  may  be  used  in 
them. 

The  Hardware  Type  of  "three-way"  corner  construction 
of  box  shown  in  figure  3,  Plate  XIV,  is  largely  used  for  hard- 
ware. This  type  is  well  adapted  to  boxes  carrying  heavy 
loads ;  and  for  boxes  in  which  the  maximum  dimension  is  not 
more  than  two  times  the  minimum  dimension.  It  is  better 
practice,  however,  to  have  the  dimensions  as  nearly  equal  as 
possible.  When  the  difference  between  the  minimum  and 
maximum  dimensions  becomes  excessive  some  other  style  of 
box  or  crate  should  be  used.  All  the  faces  must  be  made  of 
material  of  the  same  thickness ;  and  since  all  nails  are  driven 
into  the  edges  of  boards  constituting  the  faces  of  the  box,  it  is 
necessary  that  the  material  be  thick  enough  to  prevent  its 
being  split  by  these  nails.  It  is  not  considered  feasible  to 
make  a  box  of  this  type  out  of  material  less  than  y2  inch  in 
thickness. 

An  advantage  of  the  "three-way"  construction  is  that 
each  face  has  nails  driven  in  it  in  two  directions,  those  driven 
through  its  ends  perpendicular  to  its  face  being  at  right  angles 
to  those  driven  into  and  perpendicular  to  its  edges.  A  fur- 
ther and  probably  greater  advantage  is  that  nails  are  driven 
into  the  side  grain  of  the  wood. 

One  objection  to  the  "hardware  type"  of  box  is  that  in 
closing  it  after  packing,  four  edges  must  be  nailed.  The 
boards  meeting  at  these  edges  are  so  arranged  that  nails  must 
be  driven  in  three  directions,  which  makes  much  turning  and 
handling  of  the  box  necessary,  especially  if  a  nailing  machine 
is  used  for  the  work.  In  closing  other  types  of  nailed  boxes, 
the  nails  are  all  driven  in  one  direction  even  though  they  may 
be  distributed  along  four  edges  of  one  face. 

Lock-Corner  Boxes — The  box  shown  in  Style  6,  Plate 
III,  is  of  a  type  in  which  the  sides  and  ends  -are  joined  by  a 
series  of  tenons  which  interlock  and  are  called  "locks." 

These  locks  are  held  together  by  gluing  and  the  top  and 
bottom  are  fastened  in  some  other  way.  This  method  of  con- 
struction allows  the  use  of  thinner  material  in  the  ends  than 
is  possible  with  a  nailed  box  (Style  1)  properly  designed  for 
carrying  the  same  contents.  The  lock  corner,  if  properly 
glued,  gives  a  more  rigid  box  than  nailed  corners,  there  being 
no  appreciable  distortion  before  failure  occurs.  In  lock-cor- 


BOX   DESIGN  67 

ner  boxes  there  is  danger  that  the  ends  and  sides  will  split 
open,  or  that  failure  will  occur  in  the  joints  which  may  be 
present  in  these  ends  and  sides.1  Since  the  ends  can  be  made 
of  thinner  material  in  the  lock-corner  boxes  than  in  nailed 
boxes,  there  is  danger  that  the  desire  to  save  material  may  be 
carried  to  extremes,  with  the  result  of  making  the  end  too 
thin  for  properly  nailing  on  the  top  and  bottom. 

Tests  show  that  in  lock-corner  boxes  a  considerable  num- 
ber of  the  failures  occur  because  the  nails  pull  from  or  split 
the  edges  of  the  thin  ends,  locks  open,  ends  split,  and  matched 
joints  lack  sufficient  strength.  The  ends  of  lock-corner  boxes 
are  longer  than  those  of  nailed  boxes  because  of  the  addi- 
tional length  necessary  for  forming  the  locks.  This  extra 
length  is  equal  to  twice  the  thickness  of  the  side  boards  plus 
enough  for  trimming  after  gluing.  The  sides  also  need  enough 
extra  material  for  trimming  after  gluing. 

Dovetail  Boxes — The  dovetail  construction  shown  in 
figure  2,  Plate  VII,  is  used  to  a  limited  extent  for  expensive 
boxes,  returnable  boxes,  chests,  etc.,  but  such  construction  is 
more  common  in  cabinet  work  and  furniture.  The  top  and 
bottom  of  the  boxes  may  be  fastened  by  any  desirable  method. 
In  figure  1,  Plate  VII,  are  shown  the  tenons  as  they  appear 
on  two  pieces  before  being  joined  to  form  a  corner. 

One  point  of  superiority  of  the  dovetailed  corner  in  com- 
parison with  the  lock-corner  is  the  advantage  of  the  wedging 
action  in  preventing  failure  as  described  in  connection  with 
Style  6,  Plate  III,  but  it  requires  more  complicated  machinery 
to  produce  the  dovetailed  corner. 

The  disadvantages  due  to  thin  ends,  joint  failures,  etc., 
in  dovetailed  corners  are  very  similar  to  those  in  lock-corners. 

Wirebound  Boxes — The  stock  in  the  sides,  top,  bottom, 
and  ends  of  the  boxes  shown  in  figures  1  and  3,  Plate  VIII,  is 
called  sheet  material  and  it  is  usually  made  of  rotary-cut 
stock,  although  resawed  lumber  is  used  occasionally. 

Figure  4,  Plate  VIII,  shows  a  mat  for  a  "4-one"  box  as 
delivered  by  a  stitching  or  fabricating  machine  ready  to  be  as- 
sembled with  the  end  panels,  or  shipped  in  this  form  to  the 
consumer.  The  cleats  are  held  to  the  sheet  material  by  the 
staples  which  pass  over  the  wires,  through  the  sheet  material, 
and  have  their  points  firmly  held  in  the  cleats.  Staples  not 
driven  -into  cleats  are  clinched  on  the  inside  surface  of  the 
sheet  material.  Staples  over  all  wires  should  be  spaced  from 

JSee  page  43  for  discussion  of  matched  joints. 


68  WOODEN  BOX  AND    CRATE   CONSTRUCTION 

1^4  to  2^4  inches  apart.  It  has  been  found  that  with  l^-inch 
spacing,  the  end  binding  wires  do  not  slip  off  the  corners  of 
the  box  as  frequently  as  when  the  spacing  is  larger.  The  end 
pieces  are  stapled  or  nailed  on  the  inside  surface  of  three  of 
the  cleats  when  the  box  is  assembled,  the  remaining  cleat  on 
each  end  being  attached  only  to  the  top  as  shown  in  figure  6, 
Plate  VIII.  The  binding  wires  are  twisted  together  near  one 
edge  of  a  side,  to  close  the  box. 

There  are  several  styles  of  end  joints  for  the  cleats  in 
wirebound  boxes.  The  mortise  and  tenon  now  in  general  use 
and  the  step-mitre  are  shown  in  figure  4,  Plate  VII.  The 
step-mitre  is  the  older  method  but  has  at  the  present  time 
been  almost  entirely  abandoned  in  favor  of  the  mortise  and 
tenon  joint.  Cleats  with  plain  mitred  ends  are  also  coming 
into  use.  They  are  more  economical  to  manufacture  than 
other  types  and  are  very  satisfactory  for  containers  for  some 
commodities. 

An  advantage  of  the  step-mitred  and  plain  mitred  cleats 
is  that  they  allow  staples  to  be  driven  much  nearer  the  ends 
of  the  cleats,  which  aids  materially  in  preventing  the  binding 
wires  from  being  forced  off  the  corners  of  the  box.  An  ad- 
vantage of  the  mortise  and  tenon  joint  is  that  it  prevents 
lateral  movement  of  the  cleats  respecting  each  other  and  thus 
makes  a  box  which  is  more  rigid  than  one  made  with  either 
style  of  mitred  cleats. 

Cleats  for  the  smaller  wirebound  boxes  are  usually  made 
approximately  ^4  by  -JJ  inch  in  cross  section.  The  resist- 
ance of  the  box  to  destructive  hazards  encountered  in  service 
is  only  slightly  improved  by  increasing  the  width  of  the  cleats 
to  1T36  inches. 

The  end  construction  of  wirebound  boxes  may  be  mate- 
rially strengthened  by  the  addition  of  battens.  The  size,  num- 
ber, position  and  method  of  fastening  battens  depends  very 
largely  on  the  severity  and  location  of  the  thrusts  transmitted 
to  the  ends  by  the  contents  of  the  boxes.  An  arrangement  of 
battens  which  has  been  tested  at  the  Forest  Products  Labora- 
tory is  shown  in  figures  1  and  2,  Plate  VIII.  These  battens 
protect  and  strengthen  the  end  material,  increase  the  rigidity 
of  the  box,  add  strength  to  the  box  to  resist  vertical  compres- 
sion, such  as  occurs  when  a  box  is  subjected  to  an  exterior 
load  as  in  the  bottom  layer,  make  the  corner  construction 
more  rigid,  and  tend  to  maintain  the  relative  position  of  the 
cleats  in  the  step-mitre  construction,  and  also  in  the  mortise 


BOX   DESIGN 


69 


and  tenon  construction  after  either  the  tenon  or  the  sides  of 
the  mortise  have  failed.  The  amount  of  strength  added  by 
these  battens  increases  as  the  width  of  the  battens  increases 
to  a  maximum,  varying  from  \l/2  to  2  inches.  The  thickness 
remains  constantly  equal  to  that  of  the  cleats.  Battens  much 
smaller  can  not  be  properly  nailed  and  neither  larger  battens 
nor  solid  ends  add  appreciably  to  the  serviceability  of  a  box, 


FIG.  21 — Nailed  box  showing  panel  style  of  construction. 

as  the  ends  are  then  too  strong  and  Out  of  balance  with  the 
other  parts.  In  any  case,  battens  must  be  securely  nailed  in 
order  to  get  the  greatest  increase  in  strength.  The  battens 
on  the  Fassnacht  type  of  box,  figure  1,  Plate  VIII,  have  a 
tenon  on  each  end  and  a  tongue  on  one  edge  which  fit  into 
grooves  in  the  edges  of  the  cleats.  This  construction  mate- 
rially assists  the  nails  in  holding  the  battens  in  place. 

Inside  liners  or  corner  cleats,  as  shown  in  figure  5,  Plate 
VIII,  strengthen  the  box  to  some  extent. 

The  sheet  material  of  wirebound  boxes  is  rather  easily 
punctured  by  the  corners  of  other  boxes  and  projecting  ob- 


70  WOODEN  BOX  AND   CRATE   CONSTRUCTION 

jects,  and  is  not  adaptable  for  commodities  which  are  liable 
to  be  seriously  injured  by  such  hazards. 

Wirebound  boxes  are  made  of  thin  material,  and  are, 
therefore,  economical  in  the  use  of  wood.  They  can  be 
shipped  in  the  mat  (figure  4,  Plate  VIII)  or  knocked  down 
form,  and  can  be  assembled  at  the  point  of  filling  with  less 
work  than  is  required  to  nail  shooks1  together.  They  weigh 
less  than  other  wooden  boxes  adaptable  to  the  service  and 
made  of  the  same  wood.  Special  tools  have  been  devised  for 
efficiently  twisting  the  wires  for  closing  wirebound  boxes. 

Panel  Boxes — Boxes  of  the  type  shown  in  figure  21  are 
used  to  a  considerable  extent.  The  panels  are  made  of  ply- 
wood, three-ply  stock  being  most  generally  used.  The  ply- 
wood is  nailed  to  cleats  or  battens  at  each  edge  to  form  the 
panels  and  these  panels  are  then 'nailed  together  through  the 
cleats  to  form  the  box.  This  construction  makes  a  box  of 
light  weight  which  if  properly  nailed  is  much  tighter  and 
more  rigid  than  a  wirebound  box.  Since  the  panels  are  of 
plywood,  the  weakening  effect  of  a  defect  which  occurs  in 
one  of  the  plies  is  largely  annulled  by  the  adjacent  sound 
material  of  the  other  plies.  The  construction  is,  therefore, 
more  uniform  than  any  type  of  box  made  of  the  common 
grades  of  box  lumber  or  single-ply  veneer. 

Plywood  equal  in  thickness  to  lumber  offers  much  more 
resistance  to  puncturing  and  therefore  is  more  desirable  for 
boxes  carrying  commodities  which  will  be  damaged  by  that 
hazard.  Plywood  also  shrinks  very  little,  and  does  not  split 
or  pull  away  from  nails. 

FACTORS  DETERMINING  THE  AMOUNT  OF  STRENGTH 

REQUIRED 

Contents — With  contents  made  up  of  an  equal  number 
of  units,  identical  in  size  and  shape,  having  similar  properties 
but  different  weights,  and  packed  in  boxes  of  the  same  inside 
dimensions,  it  is  evident  that  the  heavier  commodity  will  re- 
quire a  stronger  box  to  withstand  equivalent  amounts  of 
rough  handling. 

The  details  of  a  box  to  give  this  additional  strength  can 
be  most  readily  determined  by  a  series  of  tests  on  various 
boxes  of  different  design.  Contents  which  will  themselves 
absorb  considerable  shock  will  materially  prolong  the  life  of 

lfThe    ends,    tops,    bottoms    and    sides    of    wooden    boxes    before    assembling    are 
called    shooks. 


BOX    DESIGN  71 

a  container.  It  has  been  demonstrated  by  tests  that  a  box 
containing  60  pounds  in  No.  3  food  cans  will  fail  more  quickly 
under  test  than  an  identical  box  filled  with  the  same  weight  of 
sand  and  sawdust  in  bulk. 

Thus  the  nature  of  the  commodity  or  inner  containers 
has  a  marked  influence  on  the  degree  of  strength  required  in 
a  box  for  performing  a  specified  service. 

If  a  box  is  packed  with  contents  consisting  of  a  few  units 
of  rectangular  section  there  is  a  tendency  for  these  units 
to  maintain  their  relative  positions  and  thus  prevent  bending 
of  the  box  boards  because  of  the  arching  effect  produced. 

Boxes  for  carrying  one  rigid  object  of  rectangular  shape 
need  form  only  a  protecting  envelope  with  perhaps  little 
strength.  Thus  the  strength  of  a  box  in  some  respects  may 
be  diminished  in  proportion  to  the  amount  of  resistance 
offered  by  the  contents  to  injury  and  deformation. 

Hazards  of  Transportation — Nothing  has  more  influence 
on  determining  the  degree  of  strength  required  in  a  box  than 
the  hazards  of  transportation.  They  usually  tend  to  cause 
failure  in  boxes  by  one  or  more  of  three  actions,  viz.,  weav- 
ing or  wrenching,  puncturing  or  breaking  various  parts,  or 
collapsing.1  The  collapsing  action  may  occur  as  diagonal 
compression  between  opposite  corners  or  opposite  edges,  or 
as  compression  perpendicular  to  the  ends,  sides,  top,  and  bot- 
tom. Boxes  which  are  dropped,  thrown,  and  rolled  when 
being  handled  by  hand  may  encounter  all  of  these  hazards, 
the  severity  of  which  will  depend  on  the  care  exercised  in  do- 
ing the  work.  The  hazards  that  boxes  are  subjected  to  in 
being  conveyed  by  motor  trucks  in  long  distance  transporta- 
tion may  result  in  considerable  twisting,  weaving,  and  jam- 
ming of  the  boxes,  and  there  may  be  destructive  compressive 
stresses  transmitted  to  the  boxes  at  the  bottom  of  the  load. 

The  hazards  of  shipping  by  freight  are  at  times  very 
severe,  especially  those  occurring  during  the  switching  and 
making  up  of  trains.  In  cars  containing  a  miscellaneous  lot 
of  commodities,  loaded  with  little  thought  of  proper  arrange- 
ment and  blocking  so  that  the  stronger  packages  should  re- 
ceive the  severest  strains,  there  will  most  surely  be  a  large 
loss  from  damaged  goods.  The  contents  of  cars,  if  not  well 
braced  in  position,  receive  severe  weaving  and  wrenching 
strains  and  may  also  be  subjected  to  serious  compressive  and 
puncturing  stresses. 


aSee  page 


72  WOODEN  BOX  AND    CRATE   CONSTRUCTION 

Destructive  conditions  due  to  the  elements,  especially 
moisture,  are  apt  to  be  experienced  by  boxes  in  transit.  Such 
conditions  may  be  encountered  at  loading  points  where  plat- 
forms and  wharves  are  not  covered,  at  prepaid  shipping 
points  in  the  country  where  there  are  no  railroad  agents,  and 
in  transit  by  boats,  barges,  trucks,  wagons,  pack  animals,  and 
refrigerator  cars. 

The  strength  requirements  for  export  shipment  are  much 
greater  than  for  domestic  shipment ;  in  fact,  export  shipments 
may  undergo  all  the  hazards  of  domestic  shipments  previous 
to  arriving  at  the  wharf  for  loading ;  and  after  reaching  a  for- 
eign port  there  may  be  a  long  journey  inland. 

The  stevedores  who  handle  export  shipments  pay  little 
attention  to  proper  handling  of  freight,  with  the  result  that 
weak  packages  and  those  containing  fragile  materials  are 
tossed  and  thrown  about  with  heavier  and  stronger  ones. 
Cargo  hooks  are  indiscriminately  used  on  packages,  which 
are  punctured  by  them  and  the  contents  injured.  In  many 
foreign  ports  the  stevedores  are  people  who  can  not  read 
directions  that  may  be  printed  on  packages  regarding  the 
nature  of  the  contents  and  directions  for  handling,  and  thus 
all  containers  are  treated  much  alike. 

One  method  of  loading  and  unloading  ships  is  by  the  use 
of  cargo  nets.  These  are  large  nets  on  which  a  quantity  of 
boxes  are  piled  and  the  corners  of  the  net  then  drawn  together 
for  lifting  in  loading  and  unloading.  In  these  operations  the 
boxes  are  thrown  violently  together  in  the  nets  and  in  swing- 
ing into  place  over  the  ship  or  lighter  the  load  net  often 
strikes  severely  against  the  side  of  the  ship,  or  some  other 
object,  with  resulting  injuries  to  the  contents  of  the  net.  In 
emptying  the  net,  one  edge  is  often  released  several  feet  above 
the  deck,  the  contents  falling  the  remainder  of  the  distance, 
accompanied  by  a  rolling  action.  Boxes  must  be  well  con- 
structed to  endure  such  service. 

Rope,  slings,  chains,  and  grappling  irons  are  used  on 
large,  heavy  boxes.  The  chief  hazards  connected  with  their 
use  are  dropping  due  to  premature  releasing  of  the  hoisting 
device,  crushing  and  bending  action  due  to  the  manner  of 
applying  slings,  etc.,  and  striking  against  other  objects  in 
swinging  from  one  position  to  another.  Such  hazards  are 
very  common  and  provision  must  be  made  for  resisting  them 
in  boxes  for  export  shipment. 

In  many  harbors  the  ships  must  be  unloaded  by  means 


BOX   DESIGN  73 

of  lighters.  This  means  extremely  severe  handling,  especially 
at  ports  where  a  rough  sea  is  common.  An  extra  handling 
is  then  necessary  from  the  lighters  to  wharves. 

The  hazards  of  a  sea  voyage  are  the  stresses  resulting 
from  improper  stowage  in  the  ships,  the  shifting  of  a  cargo, 
and  weakening  effects  due  to  change  in  moisture  content  and 
corrosion  of  metal  parts. 

FACTORS  DETERMINING  THE  SIZE  OF  A  BOX 

Gross  Weight — The  gross  weight  for  boxes  should,  if 
possible,  be  such  as  will  make  a  reasonable  load  for  one  man 
or,  in  some  instances,  for  one  woman.  The  French  Govern- 
ment in  connection  with  war  work  fixed  the  maximum  load 
for  a  woman  at  seventy  pounds.  When  the  load  must  be 
more  than  one  person  can  handle  efficiently  it  should,  if  pos- 
sible, be  increased  to  make  a  reasonable  load  for  two.  If  the 
gross  weight  is  too  much  for  one  person  and  too  light  for  two 
the  work  of  handling  can  not  be  so  efficiently  done.  The 
weight  of  the  container  should  be  as  small  as  proper  design 
will  permit  with  the  object  of  saving  in  freight  charges  and 
box  material. 

Desired  Quantity — With  some  commodities  it  is  the 
quantity  wrhich  is  ordinarily  desired  by  the  consumer  which 
will  determine  the  size  of  the  box  to  be  used.  With  small 
boxes,  howrever,  several  of  them  may  be  in  turn  packed  in  a 
larger  box  or  crate  to  facilitate  handling  and  to  give  better 
protection  in  shipping. 

Nesting,  Disassembling,  or  Knocking  Down  Contents — 
For  some  objects,  the  size  of  the  box  must  be  larger  than  is 
ordinarily  desired  for  convenient  handling;  in  such  cases,  as 
much  nesting  and  disassembling  of  parts  should  be  done  as  is 
deemed  advisable  in  order  to  reduce  the  size  of  the  box.  Dis- 
assembling will  often  allow  parts  that  would  be  easily  broken 
to  be  packed  more  securely. 

Minimum  Displacement — In  every  case,  the  amount  of 
space  required  for  a  box,  i.  e.,  its  displacement,  should  be  as 
small  as  possible.  This  is  especially  desirable  for  export  ship- 
ments, as  rates  are  based  on  the  space  required  rather  than 
the  weight.  Probably  the  space  requirement  will  enter  more 
directly  into  rates  for  domestic  shipments  in  the  future. 
Minimum  displacement  also  means  in  most  instances  the  use 
of  a  smaller  amount  of  material  in  constructing  the  boxes 


74  WOODEN   BOX  AND    CRATE   CONSTRUCTION 

and  a  reduction  in  storage  space  required  for  them,  both  in 
shook  and  assembled  form. 

Traffic  Limitations — There  are  certain  traffic  limitations 
and  regulations  which  influence  the  design  of  some  boxes. 
The  design  of  boxes  for  shipping  explosives  and  dangerous 
articles  by  freight  is  regulated  by  the  Interstate  Commerce 
Commission.  The  size  and  weight  of  packages  for  shipment 
by  parcel  post  is  limited.  More  definite  regulations  by  traf- 
fic officials  regarding  the  method  of  boxing  and  packing  cer- 
tain commodities  would  help  to  solve  the  problem  of  obtain- 
ing more  adequate  shipping  containers. 

SPECIAL    CONSTRUCTIONS 

Protection  of  Fragile  and  Delicate  Contents — Many  com- 
modities are  extremely  susceptible  to  damage  in  transit;  too 
much  information  can  not  be  had  by  box  designers  regarding 
methods  of  packing  such  commodities  correctly. 

Protection  against  injury  by  moisture  must  be  provided 
for  some  commodities.  One  method  is  to  provide  a  water- 
resisting  paper  liner,  or  a  tight  sheet-metal  liner.  When  these 
liners  are  to  be  used,  the  space  which  they  require  must  be 
provided  for  in  the  design  of  the  box. 

Some  kinds  of  merchandise  need  to  be  packed  in  mate- 
rials that  will  not  transmit  to  the  contents  the  shocks  and 
impacts  received  by  the  box.  Among  such  packing  materials 
are  corrugated  fiber  and  straw  board,  excelsior,  strawr,  hay, 
shavings,  sawdust,  etc.  The  amount  of  space  required  for 
these  cushioning  materials  will  depend  on  the  fragility  and 
weight  of  the  commodity  and  the  seventy  of  the  hazards  of 
transportation. 

One  method  of  preventing  serious  stresses  and  shocks 
due  to  boxes  falling  on  their  corners  is  to  provide  each  corner 
with  a  bumper  of  cushioning  material.  Another  method  is 
that  of  "flotation,"  which  consists  of  packing  one  box  within 
another,  writh  the  intervening  space  between  all  faces  of  the 
boxes  filled  with  a  cushioning  material  or  some  system  of 
mechanical  spring  supporters.  In  this  problem  two  boxes  of 
proper  relative  size  and  strength  must  be  designed  and  the 
cushioning  feature  must  be  provided  for. 

The  various  individual  elements  constituting  the  con- 
tents of  some  boxes  need  to  be  prevented  by  separators  of 
some  character  from  jolting  against  each  other.  One  method 


BOX    DESIGN 


75 


is  to  form  a  series  of  cells  or  individual  compartments  for 
each  element  of  the  contents,  as  shown  in  figure  22.  Tests 
have  demonstrated  that  for  carrying  hand  grenades  cells  made 
from  corrugated  fiber  board  sustaining  175  pounds  per  square 
inch  before  puncturing,  as  recorded  by  the  Mullen,  the  Webb 
and  other  similar  testers,  are  more  efficient  than  wooden  cells 


FIG.  22 — Box   with   corrugated   fiber   board  lining  and   cells. 

made  from  -f^-inch  lumber.  The  wooden  cells  broke  up 
sooner  and  absorbed  less  shock  than  the  corrugated  fiber 
board  cells  and  thus  they  transmitted  the  shocks  of  the  con- 
tents to  the  container,  thereby  stimulating  the  action  tending 
to  injure  the  contents. 

The  character  of  the  material  composing  the  cell  will  de- 
pend on  the  nature  of  the  contents  to  be  packed.  Some  con- 
tents need  to  be  protected  from  surface  abrasions  only,  and  in 
such  cases  it  is  the  cushioning  property  that  is  desired  in  the 
cell  walls ;  for  other  contents,  much  strength  may  be  needed 
in  the  cell  walls,  as  the  contents  may  not  be  strong  enough 
to  withstand  the  pressures  which  occur  within  the  container. 

Whatever  the  material  of  which  the  cell  is  made  its  di- 
mensions should  be  such  as  to  permit  the  contents  to  fit  snug- 
ly ;  this  diminishes  the  force  of  the  impacts  tending  to  de- 
stroy both  the  cells  and  the  container,  and  also  allows  the 
total  displacement  of  the  container  to  be  reduced: 

In  designing  boxes  for  some  commodities  the  more  fragile 
and  delicate  parts  must  be  separated  from  the  stronger  parts 


76  WOODEN  BOX  AND   CRATE   CONSTRUCTION 

by  partitions  of  considerable  strength.  In  some  instances,  the 
amount  of  material  in  a  box  can  be  reduced  and  a  more  satis- 
factory container  secured  by  using  one  or  more  partitions. 
Partitions  may  be  placed  horizontally  as  well  as  vertically 
and  also  may  be  left  unfastened  so  as  to  facilitate  removal. 

Some  articles  can  be  shipped  to  advantage  by  using  trays 
for  supporting  them  in  their  boxes.  Trays  may  be  constructed 
of  plywood  or  of  lumber.  In  using  lumber  for  trays  in  some 
instances  it  is  well  to  put  splines  in  their  ends  to  prevent  split- 
ting and,  to  some  extent,  warping.  There  is  much  less 
change  in  size  and  shape  of  symmetrically  constructed  ply- 
wood than  lumber  when  subjected  to  change  in  moisture  con- 
tent. It  may  be  desirable  at  times  to  use  sheet  metal,  wall 
board,  etc.,  for  trays. 

When  several  articles  of  varied  shape  with  some  delicate 
parts  attached  are  to  be  packed  in  the  same  box,  a  series  of 
internal  braces,  supporters,  separators,  etc.,  will  have  to  be 
designed.  Good  examples  of  such  boxes  are  those  for  carry- 
ing rifles,  machine  guns,  valuable  tools,  scientific  instruments, 
and  machines. 

Vermin — Some  commodities  are  attacked  by  various 
species  of  vermin  in  storage  and  transit,  especially  during 
sea  voyages.  It  may  devolve  on  the  box  designer  to  devise  a 
style  of  box  construction  or  inside  lining  which  will  resist 
the  ravages  of  such  destructive  pests. 

Thieving — Great  losses  occur  from  theft  while  goods  are 
in  transit.  The  problem  is  a  very  serious  one  and  much  at- 
tention should  be  given  to  the  design  of  boxes  which  can  not 
be  readily  opened  and  reclosed  without  detection. 

The  prevention  of  thievery  is  largely  a  matter  of  police 
protection.  Seals,  straps,  and  more  rigid  construction  as  de- 
scribed in  other  parts  of  this  book  are  valuable  in  that  theft 
is  more  quickly  discerned,  and  the  thief  is  deterred  by  his 
knowledge  of  the  box  construction. 


CHAPTER  III 
CRATE   DESIGN 

FACTORS  AFFECTING  STRENGTH  OF  CRATES — FACTORS  DETERMIN- 
ING AMOUNT  OF  STRENGTH  REQUIRED  IN  CRATES — -FACTORS 
INFLUENCING  THE  SIZE  OF  CRATES. 

Many  of  the  factors  influencing  the  details  of  design  for 
boxes  will  similarly  affect  the  design  of  crates.  Among  these 
are  the  availability,  supply,  and  cost  of  lumber,  manufactur- 
ing limitations,  and  balanced  construction  which  are  discussed 
in  Chapter  II. 

FACTORS  AFFECTING  STRENGTH   OF  CRATES 
INFLUENCE  OF  STYLES  OF  CRATES  ON   STRENGTH 

The  serviceability  of  crates  is  vitally  affected  by  the  style 
of  construction,  especially  the  method  of  joining  the  frame 
members  at  the  corners  of  the  crates  and  the  kind  of  fasten- 
ings used. 

Types  of  Corner  Construction — In  Figures  1,  2  and  3, 
Plate  XI,  are  shown  three  types  of  the  "three-way"  corner 
construction  for  joining  the  frame  members  of  crates.  If 
only  the  types  of  construction  are  considered,  that  shown  in 
figure  1,  Plate  XI,  is  the  most  desirable  because  all  of  the 
frame  members  are  fastened  in  the  same  way.  In  figures  2 
and  3,  Plate  XI,  the  arrangement  of  the  members  is  differ- 
ent; but  these  types  may  be  desirable  when  crating  some  ob- 
jects. Material  which  is  approximately  square  in  cross  sec- 
tion is  preferred  in  these  two  constructions.  There  are  sixteen 
different  variations  of  the  three-way  corner.  (See  Plate  XII.) 

An  advantage  of  the  three-way  corner  is  its  symmetrical 
construction  in  which  the  members  are  fastened  together  in 
such  a  way  that  through  each  member  nails  or  bolts  may  be 
passed  in  two  directions  at  right  angles  to  each  other,  thus 
uniting  the  members  securely  and  reducing  the  danger  of 
their  being  split  by  the  bolts  or  nails;  nails  or  bolts  passing 

77 


78  WOODEN  BOX  AND   CRATE   CONSTRUCTION 

through  the  members  in  one  direction  resist  the  splitting  ac- 
tion of  those  at  right  angles  to  them. 

Another  advantage  of  the  three-way  corner  is  the  arrange- 
ment of  the  members  so  that  only  one  thickness  of  frame 
material  intervenes  between  the  contents  and  the  outer  sur- 
face of  the  crate,  thereby  in  most  cases  keeping  the  displace- 
ment lower  than  is  possible  with  other  styles  of  crates. 

In  figure  5,  Plate  XI,  is  shown  a  type  of  crate-corner 
construction  which  is  largely  used  but  which  is  inferior  to 
the  three-way  corner  construction  in  at  least  two  respects; 
viz.,  there  are  two  thicknesses  of  the  material  outside  the  ob- 
ject on  two  faces  of  the  crate,  which  increases  the  total  dis- 
placement of  the  crate,  and  some  of  the  members  have  nails 
through  them  in  only  one  direction,  so  that  they  are  not  held 
SO  securely  to  the  other  members  as  they  would  be  with  the 
three-way  corner  construction.  The  addition  of  a  second 
piece  along  one  edge,  as  shown  in  figure  6,  Plate  XI,  gives 
additional  strength  to  the  corner,  makes  the  combined  mem- 
ber stiffer  and  stronger,  and,  in  some  instances,  gives  addi- 
tional support  and  protection  to  the  contents. 

Frame  Members — The  frame  members  of  a  crate  as  shown 
in  figures  3  and  4,  Plate  XIII,  constitute  the  foundation  to 
which  all  other  parts  are  connected  either  directly  or  indirectly. 
The  frame  members  must  have  sufficient  size  and  strength  to 
form  a  foundation  skeleton  upon  which  to  complete  a  crate 
that  will  carry  the  contents  to  its  destination  with  little  danger 
of  injury,  even  though  severe  hazards  are  encountered.  Not 
only  the  vertical  and  horizontal  members  should  be  strong 
enough  to  support  the  exterior  loads  to  be  put  upon  a  crate  in 
storage  or  transit,  but  also  the  diagonal  and  cross  bracing1 
must  be  sufficient  and  so  arranged  as  to  distribute  the  stresses 
and  hold  the  other  crate  members  in  proper  position.  Without 
proper  bracing  it  is  practically  impossible  to  build  a  crate  that 
will  not  weave  or  skew  in  transportation,  even  though  the 
three-way  corner  construction  is  used  and  the  crate  when 
freshly  made  appears  quite  rigid.  This  skewing  and  weaving 
is  largely  responsible  for  such  damage  as  rubbing  of  varnished 
surfaces,  and  the  breaking  of  legs  and  other  projecting  parts 
of  furniture. 

The  amount  that  any  piece  will  support  in  compression, 
considering  that  it  is  a  column  so  short  or  so  firmly  braced 
that  there  is  no  danger  of  failure  by  buckling  or  bending,  will 

1See  page  84  relative  to  internal  braces.  , 


CRATE  DESIGN  79 

be  found  by  multiplying  the  area  of  the  cross  section  of  the 
piece  in  square  inches  by  the  safe  allowable  load  for  the  mate- 
rial in  pounds  per  square  inch.1  The  safe  allowable  load  is 
always  considerably  less  than  the  ultimate  load  that  a  mate- 
rial can  support.  The  horizontal  top  members  must  be  strong 
enough  to  sustain  between  points  of  support  such  bending 
loads  as  may  be  placed  on  them  in  storage  or  shipment. 

Skids — The  lower  horizontal  frame  members  running 
lengthwise  of  a  crate  usually  form  the  skids.  The  skids  sup- 
port the  contents  directly,  or  indirectly  through  intervening 
members,  and  also  the  weight  of  the  crate  and  superimposed 
loads,  unless  the  lower  ends  of  the  vertical  members  rest  on 
some  other  support.  For  heavy  objects,  which  must  be 
moved  on  rollers  and  hoisted  with  chains  or  slings,  the  skids 
should  have  extra  pieces  added  to  them  as  shown  in  figure  4, 
Plate  XIII,  which  will  increase  the  bending  resistance  and 
provide  a  bearing  surface  for  the  rollers,  chains,  etc.  The 
ends  of  these  additional  pieces  should  be  beveled  or  scarfed 
to  facilitate  sliding  or  the  passage  of  the  skids  onto  rollers, 
and  should  also  extend  outward  underneath  the  vertical  mem- 
bers of  the  crate  to  support  them  as  indicated,  for  otherwise 
any  load  put  on  the  crate  will  produce  compression  and  shear 
on  the  fastenings  which  connect  the  vertical  members  to  the 
skids.  These  extra  pieces  must  also  be  securely  fastened 
throughout  their  length  to  the  frame  members  in  order  to 
make  the  combined  parts  act  more  nearly  as  a  single  piece 
skid,  which  increases  the  resistance  to  horizontal  shear  and 
bending.  When  a  crate  is  being  moved,  it  may  at  some  time 
be  supported  by  rollers  or  slings  in  such  a  way  as  to  produce 
serious  bending  moments  in  the  skids.  To  calculate  the 
weight  that  a  skid  will  support  when  resting  on  a  roller  mid- 
way between  points  of  loading,  the  formula  for  beam  loading 
given  in  U.  S.  Department  of  Agriculture  Bulletin  556, 
"Mechanical  Properties  of  Woods  Grown  in  the  United 
States,"  may  be  used. 

Bracing  Long  Crates — When,  in  a  long  crate,  each  skid 
and  the  top  horizontal  frame  member  are  securely  fastened 
together  by  several  cross  members  and  substantial  diagonal 
or  cross  braces  are  provided,  a  truss-like  form  of  construction 
is  obtained  which  greatly  increases  the  resistance  of  the  crate 
to  bending.  A  side  view  of  such  a  crate  is  shown  in  figure  1, 


iSee  United  States  Department  of  Agriculture  Bulletin  556,  "Mechanical  Prop- 
erties of  Woods  Grown  in  the  United  States,"  10  cents  per  copy,  obtainable  from 
Superintendent  of  Documents,  Washington,  D.  C. 


80  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

Plate  XIII.  To  obtain  the  number  of  cross  members  and 
number  of  angular  braces  or  sets  of  cross  bracing  for  any 
face  of  a  crate,  use  the  following  rule : 

Divide  the  longer  dimensions  of  any  face  by  its  shorter 
dimension,  and, 

1.  If  the  result  is  less  than  one  and  one-half  use  one 
angular  brace  or  one  set  of  cross  bracing ; 

2.  If  the  result  is  one  and  one-half  or  more  and  less  than 
three,  use  one  cross  member  and  two  angular  braces  or  two 
sets  of  cross  bracing; 

3.  If   the   result   is   three   or   greater,   use   a   number  of 
angular  braces  or  sets  of  cross  bracing  equal  to  the  largest 
whole  number  in  the  result.     The  number  of  cross  members 
will  be  one  less.      (See  figures   1   and  2,  Plate  XIII.)     This 
method  of  figuring  the  number  of  braces  to  be  used  divides 
the  face   of  the   crate   into   panels   which   are   approximately 
square,  the  braces  making  angles  of  about  45  degrees  with 
horizontal   members,   which   is   considered   the  best   practice. 

Fitting  and  Fastening  Braces — In  cutting  the  end  of  a 
diagonal  or  cross  brace,  the  toe  should  be  made  with  a  flat 
surface  or  butt  against  the  adjacent  member.  (See  figure  4, 
Plate  XI.)  Care  should  be  exercised,  however,  that  the 
distance  from  the  toe  to  the  heel  is  great  enough  to  provide 
for  properly  nailing  or  bolting  the  brace. 

The  thickness  of  a  diagonal  brace,  or  a  set  of  cross  braces, 
figure  4,  Plate  XIII,  plus  the  thickness  of  sheathing  when 
used,  figure  2,  Plate  XIII,  should  not  exceed  the  thickness  of 
the  frame  members. 

When  cross  bracing  is  put  on  as  in  figure  4,  Plate  XI, 
the  outside  brace  should  have  blocks  between  its  ends  and 
the  frame  members  to  which  it  is  nailed  unless  the  length  of 
the  brace  is  such  that  the  amount  of  bending  produced  by 
omitting  the  blocks  will  not  seriously  strain  the  braces.  The 
initial  bending  produced  by  omitting  the  blocks  will  tend  to 
increase  the  danger  of  failure  by  buckling  when  a  brace  is 
subjected  to  endwise  compression.  Such  blocks  as  are  used 
under  braces  should  preferably  extend  for  some  distance 
along  their  length  and  be  securely  fastened  to  them  to  min- 
imize the  danger  of  the  blocks  being  split  and  getting  out  of 
place.  Cross  braces  should  be  securely  fastened  together  at 
the  point  of  intersection.  Nails  driven  through  and  clinched, 
or  bolts,  are  preferable  for  this  fastening. 

Scabbing — In  figure  2,  Plate  XIII,  the  use  of  scabbing  is 


CRATE  DESIGN  81 

shown.  Scabbing  consists  of  a  piece  nailed  across  a  joint  on 
the  faces  of  two  pieces  to  unite  them  securely.  It  is  similar 
to  a  plaster  joint  in  a  timber  construction.  The  chief  require- 
ments of  pieces  which  are  to  be  used  for  scabbing  is  that  they 
possess  sufficient  strength  and  resistance  to  being  split  or 
sheared  by  nails  or  bolts.  It  is  well  to  have  the  scabbing  in 
this  particular  construction  wide  enough  to  support  the  sides 
of  the  toes  of  the  braces,  as  indicated  in  the  figure. 

Sheathing — The  purpose  of  sheathing  is  to  protect  the 
contents  from  the  elements,  reduce  losses  of  small  parts  by 
thieving,  and  prevent  injuries  to  contents  from  external  ob- 
jects. Sheathing  when  securely  nailed  also  strengthens  a 
crate  to  a  considerable  extent,  especially  if  it  is  run  in  a 
diagonal  direction.  It  may  be  put  entirely  outside  of  the  frame 
members  and  bracing.  A  poorer  grade  of  material  can  be  used 
for  sheathing  than  for  the  other  parts  of  a  crate.  Usually 
matched  lumber  surfaced  at  least  on  one  side  and  with  the 
surfaced  side  exposed  to  receive  shipping  directions  and  ad- 
vertising is  preferred. 

Battens  on  crates  are  used  for  additional  supports  for 
sheathing  and  for  holding  on  waterproof  coverings. 

PHYSICAL  PROPERTIES  OF  WOOD  AFFECTING  STRENGTH. 

Relative  Thickness  of  Material — For  general  crating  work 
the  harder  woods  of  Groups  2,  3,  and  41  may  be  25  per  cent 
less  in  thickness  than  material  from  Group  1  to  give  approx- 
imately equal  strength. 

Moisture  Content — The  moisture  content  in  crate  lumber 
should  be  within  limits  of  from  12  to  18  per  cent.  Decreases 
in  moisture  content  after  construction  will  loosen  the  fasten- 
ings and  joints,  cause  members  to  check,  allow  internal  braces 
to  become  loose,  and  diminish  the  effectiveness  of  the  sheath- 
ing as  a  protection  to  the  contents. 

Defects — In  crate  members  and  braces,  defects  must  be 
more  rigidly  excluded  than  in  lumber  for  boxes,  as  the  parts 
must  have  more  uniform  strength.  Except  in  special  cases, 
such  defects  as  are  allowed  in  box  material  can  be  permitted 
in  crate  sheathing.  Defects  are  discussed  fully  in  Chapter  II. 

Nailing  and  Bolting  Qualities  of  Wood — Since  the  main 
fastenings  in  crates  come  at  the  ends  of  the  various  members 
it  is  important  that  lumber  which  is  not  easily  split  by  nails 


3See  page  100  for  grouping  of  woods  for  box  construction. 


82  WOODEN  BOX   AND    CRATE   CONSTRUCTION 

or  bolts  be  used.  It  is  a  well-known  fact  that  in  many  wooden 
structures  the  great  weakness  and  danger  of  failure  is  due  to 
inability  to  get  the  ends  of  the  various  members  in  tension 
fastened  in  such  a  way  as  to  stress  them  even  to  a  point  of 
safe  loading.  For  crate  construction,  lumber  which  is  warped 
or  twisted  is  more  objectionable  than  similarly  affected  mate- 
rial would  be  in  box  work.  Considerable  initial  stress  is 
produced  in  a  seriously  warped  timber  when  it  it  is  forced  to 
assume  approximately  a  normal  shape.  This  necessarily  re- 
duces the  ability  of  the  piece  to  resist  external  forces. 

The  various  factors  which  influence  the  holding  power 
of  nails  and  the  strength  of  nailed  joints  are  discussed  on 
pages  51  and  101. 

Bolts,  when  holes  of  proper  size  are  bored  for  them, 
do  not  produce  a  wedging  action  which  tends  to  split  the 
members  of  a  crate  as  do  large  nails  or  spikes.  The  clamping 
action  produced  by  bolts  holds  the  members  together  more 
securely  than  nails,  which  are  dependent  in  such  action  upon 
the  friction  of  their  shanks  in  the  wood  of  the  member  hold- 
ing the  points.  In  case  of  shrinkage  and  splitting  of  the 
wood,  bolts  may  be  tightened  and  will  continue  to  be  more 
effective  than  nails  under  similar  conditions. 

Fastenings  and  Reinforcements — Because  of  the  open 
construction  of  crates  the  total  amount  of  space  allowed  for 
fastening  is  less  than  for  boxes  of  the  same  size  and  there- 
fore the  fastenings  on  crates  must  be  relatively  stronger. 
Much  of  the  discussion,  however,  pertaining  to  nails  in  the 
section  on  "Fastenings  and  Reinforcements,"  page  53,  will  ap- 
ply to  the  nails  used  in  crating  work. 

Nails  and  Nailing — The  size  of  cement-coated  nails  recom- 
mended for  the  various  thicknesses  of  lumber  used  in  all 
parts  of  a  crate  is  given  in  Table  13. 

Frame  members  and  braces  should  have  not  less  than 
two  nails  in  any  end  and  as  many  additional  nails  as  can  be 
driven  without  weakening  the  joints  by  splitting  the  mem- 
bers. Nails  in  sheathing  should  be  staggered,  the  distance 
between  their  centers,  measured  along  the  length  of  the  piece 
nailed  to,  being  equal  to  J4  inch  for  each  penny  of  the  nails 
used.  Sheathing  should  be  nailed  to  all  members  of  the  crate 
which  it  crosses. 

It  is  often  supposed  that  driving  nails  at  a  slant  results 
in  an  increased  resistance  to  withdrawal  and  to  shear  in  the 
joints.  While  in  some  special  cases  this  belief  is  supported 


CRATE  DESIGN 


83 


by  test  results,  tests  show  that  in  most  cases  slanting  causes 
a  loss  of  efficiency. 

The  efficiency  of  nails  and  the  number  of  nails  that  can 
be  used  without  splitting  can  be  very  considerably  increased 
by  boring  holes.  The  boring  of  holes  gives  definite  bearing 

TABLE   13.    SIZE  OF  NAILS   FOR  CRATING 


Thickness  of  lumber  in  inches 

Penny    of    cement- 
coated     box      nails1 

Against  nail  head 

Holding  nail  point 

Group  I 
woods2 

Group  II 
woo  ds2 

1/2 
1/2     to       5/8 
3/4 
13/16  to       7/8 
1 
1  1/8     to  1  1/4 
1  3/8     to  1  1/2 
1  5/8     to  1  3/4 
1  7/8     to  2 
2  1/8     to  2  1/4 

1/2    to  5/8 
3/4     and  over 
3/4     and  over 
13/16  and  over 
1             and  over 
1   1/8     and  over 
1  3/8     and  over 
1  5/8     and  over 
1  7/8     and  over 
21/8     and  over 

6 
'7 
8 
9 
10 
12 
16 
20 
30 
40 

5 
6 
7 
8 
9 
10 
12 
16 
20 
30 

on  the  end  grain  of  the  wood,  whereas  driving  without  holes 
forces  the  wood  fibers  aside  without  affording  such  definite 
bearing.  Nails  driven  in  holes  slightly  smaller  than  their 
diameter  have  considerably  better  resistance  both  to  direct 
pull  and  to  shear  in  the  joint  than  nails  driven  without  holes. 

Under  the  repeated  shocks  and  more  or  less  constant 
weaving  action  to  which  crates  are  subjected  slender  nails 
bend  near  the  surface  of  the  pieces  joined,  and  without  loosen- 
ing the  friction  grip  toward  the  point  of  the  nail.  As  the 
diameter  of  the  nail  is  increased  the  stiffness  also  increases, 
and  at  a  much  more  rapid  rate,  and  the  deformation  of  the 
wood  and  decrease  of  the  friction  grip  progresses  toward  the 
point  of  the  nail.  Consequently,  the  larger  and  stiffer  nails 
are  in  greater  danger  of  having  their  value  destroyed  by  the 
treatment  accorded  crates  during  handling  and  shipment. 

Bolts  and  Bolting — Table  14  is  from  War  Department 
Supply  Circular  No.  22,  1918,  and  it  gives  the  relative  size  of 
bolts  to  be  used  in  crate  frames.  There  should  be  at  least 
two  bolts  in  each  end  of  frame  members.  (See  figures  1,  2, 
and  3,  Plate  XL) 

Carriage  bolts  'are  usually  preferred  for  crating  work  be- 
cause the  heads  are  oval  and  do  not  catch  on  objects,  as  do 

*See  nail  tables  on  pages   139,   140. 
2See  groups  of  woods,  page  100. 


84  WOODEN  BOX  AND   CRATE   CONSTRUCTION 

the  heads  of  machine  bolts  when  not  countersunk.  Machine 
bolts  usually  require  a  washer  under  the  head  to  give  suffi- 
cient bearing  surface.  Carnage  bolts  also  have  the  advantage 
of  a  square  shoulder  on  the  shank  adjacent  to  the  head,  which 
prevents  turning  of  the  bolt  when  drawn  into  the  wood. 
Washers,  preferably  standard  cut,  should  be  used  under  all 
nuts  to  prevent  them  from  cutting  into  the  wood.  So  far  as 

TABLE   14.    SIZE  OF   BOLTS   FOR   CRATING 


Thickness  of  frame  lumber 
in  inches 

Diameter  of  bolt 
in  inches 

1           to  1  1/2 
1  1/2  to  3 
3  and  over 

3/8 

1/2 
5/8* 

possible,  all  nuts  should  be  put  on  the  inner  side  of  joints. 
Holes  for  bolts  should  be  small  enough  for  a  drive  fit,  which 
will  make  a  more  rigid  construction. 

Lag  Screws — Lag  screws  are  not  considered  a  good  fas- 
tening in  crating  work.  They  may,  however,  be  used  should 
it  be  impossible  to  get  a  bolt  into  position  and  apply  the  nut, 
or  where  a  bolt  of  excessive  length  would  be  required.  In 
using  lag  screws,  a  hole  should  first  be  bored  equal  to  the 
diameter  and  depth  of  the  shank,  and  then  the  hole  continued 
with  a  diameter  equal  to  that  at  the  root  of  the  thread  until 
the  total  depth  of  the  hole  is  equal  to  the  length  from  the 
head  to  the  end  of  the  untapered  part  of  the  thread. 

Straps — Straps  may  be  used  in  strengthening  crates.  One 
method  of  strengthening  a  corner  is  shown  in  figure  7,  Plate 
XL  Straps  are  also  used  in  some  instances  to  help  keep 
the  contents  in  position  and  support  internal  braces. 

Binding  Rods — Binding"  rods,  or  tie  rods,  may  be  run 
through  crates  in  various  directions  to  bind  the  parts  more 
securely  together.  They  are  especially  valuable  in  places 
where  much  tension  is  apt  to  be  developed  in  the  members 
and  because,  as  has  been  mentioned,  it  is  very  difficult  to  join 
wooden  members  in  such  a  way  that  their  tensile  strength 
can  be  utilized. 

Internal  Bracing — The  object  of  internal  bracing  is  pri- 
marily to  support  the  contents  in  the  crate  in  such  a  manner 
that  the  crate  may  ride  on  any  face  without  injury  to  the 


*In    very    heavy    crates,    bolts    large    than     %-inch    will    be     desirable     in     some 
instances. 


CRATE  'DESIGN  85 

contents.    If  the  contents  are  fairly  rigid  such  internal  bracing 
will  then  serve  to  strengthen  the  crate. 

Internal  bracing  should,  if  possible,  be  so  placed  that  the 
thrusts  come  against  the  end  grain  of  the  braces,  then  if 
moisture  content  of  the  braces  is  reduced  they  will  not  permit 
as  much  movement  of  the  crate  contents  as  would  have  oc- 
curred had  the  thrust  been  against  the  side  grain  of  the 
braces,  because  shrinkage  of  wood  parallel  with  the  grain  is 
negligible. 

FACTORS   DETERMINING  AMOUNT  OF  STRENGTH 
REQUIRED  IN   CRATES 

The  weight  of  the  contents  and  their  resistance  to  exter- 
nal forces  determine  to  a  great  extent  the  degree  of  strength 
that  a  crate  must  have.  If  the  contents  are  heavy  and  rigid, 
possessing  great  strength,  then  a  crate  may  be  largely  held 
in  position  and  its  shape  maintained  by  internal  braces1  set 
at  various  places  between  the  contents  and  the  crate  mem- 
bers. With  contents  which  are  more  delicate  and  possess 
little  strength,  the  crate  must  have  much  rigidity  and  strength 
so  that  it  may  be  depended  on  to  support  the  contents  prop- 
erly and  prevent  damage. 

HAZARDS  OF  TRANSPORTATION 

A  crate  must  be  strong  enough  to  prevent  damage  to  the 
contents  from  the  hazards  which  may  be  encountered  in  its 
journey.  Many  American  shippers  at  the  present  time  have 
little  conception  of  the  severity  of  the  hazards  in  export 
shipping. 

In  moving  crates  on  rollers  and  handling  with  cranes 
severe  bending 'stresses  are  apt  to  be  produced.2  Crates  when 
being  handled  by  cranes  may  also  be  dropped  or  collide  with 
other  objects  in  being  lifted  and  swung,  which  will  twist  and 
strain  them  severely. 

In  moving  crated  material  by  wagon  and  trucks,  the 
greatest  hazards  will  ordinarily  occur  in  the  process  of  load- 
ing and  unloading. 

The  hazards  to  be  guarded  against  in  shipment  of  crated 
materials  over  railroads  on  flat  cars  are  movement  of  con- 
tents in  the  crate,  movement  of  the  crate  on  the  car,  theft 
of  easily  removed  parts,  and  damage  by  the  elements. 

'See  page  84 
2See   page  78. 


86  WOODEN  BOX   AND    CRATE   CONSTRUCTION 

In  export  shipment  the  hazards  that  are  usually  met  with 
are  very  rough  handling  by  cranes  and  derricks,  the  stresses 
that  occur  due  to  the  method  of  stowage,  cargo  shifting,  and 
the  destructive  action  of  the  elements. 

FACTORS   INFLUENCING   THE   SIZE   OF   CRATES 

The  outside  dimensions  of  a  crate  will  depend  on  the 
dimensions  of  the  contents,  the  amount  of  clearance  necessary 
between  the  contents  and  the  members,  and  the  size  of  the 
members.  As  much  disassembling  of  contents  as  is  possible 
at  a  reasonable  cost  should  be  done,  in  order  to  reduce  the 
space  required. 

The  cost  of  material  for  making  crates,  storage  space 
required,  and  charges  for  export  shipment  based  on  space 
occupied,  are  some  of  the  factors  which  necessitate  reducing  the 
displacement  of  a  crate  to  the  minimum.  With  very  large 
crates  the  ability  of  the  transportation  machinery  to  move 
them  to  their  destination  without  difficulty  is  sometimes  a 
very  important  consideration. 

Before  any  large  shipments  are  ma^e,  especially  in  for- 
eign trade,  complete  information  should  be  obtained.  The 
National  Association  of  Box  Manufacturers  is  in  touch  with 
the  various  sources  of  information  as  to  the  many  require- 
ments for  shipments  to  different  foreign  countries.  These 
traffic  requirements  are  so  varied  and  voluminous  that  they 
cannot  be  included  in  this  book. 


CHAPTER  IV 
BOX  AND  CRATE  TESTING 

METHODS  OF  TESTING  AND  THEIR  SIGNIFICANCE 

Data  of  value  in  the  proper  designing  of  boxes  and  crates 
cannot  be  easily  obtained  by  observing  boxes  and  crates  as 
they  proceed  through  the  various  stages  of  commercial  serv- 
ice. Containers  which  have  failed  in  service  may  be  examined, 
but  the  causes  which  produced  the  failure  can  not  be  meas- 
ured or  readily  observed,  nor  can  the  sequence  of  failures  be 
told.  Laboratory  tests,  however,  which  closely  simulate  the 
hazards  encountered  in  commercial  transportation  service  and 
which  may  be  completely  observed  through  all  the  stages  of 
the  life  of  a  box  or  crate  as  it  passes  through  the  process  of 
testing,  give  information  as  to  the  relative  value  of  different 
details  of  construction.  Laboratory  tests  can  also  be  carried 
on  more  quickly  and  economically. 

Some  of  the  definite  phases  of  box  and  crate  construc- 
tion work  concerning  which  information  may  be  obtained  by 
testing  are  the  following: 

1.  Classification   of   woods   as   to   nailing   and   strength 
properties  for  box  construction. 

2.  Determination  of  balanced  construction.1 

3.  Determination  of  the   effect   of   different   degrees  of 
moisture   content   and   changes   in   moisture   content   on   the 
strength  of  boxes. 

4.  Comparison    of    various    methods    and    amounts    of 
reinforcing. 

.    5.     Comparison  of  different  styles  of  construction. 

6.  Determination  of  the  effect  of  various  types  of  con- 
tents and  methods  of  packing  on  the  serviceability  of  a  box. 

7.  Standardization  of  strapping  of  wooden  boxes. 

METHODS  OF  TESTING  AND  THEIR  SIGNIFICANCE 

There  are  now  three  types  of  box  tests  made  at  the  For- 
est Products  Laboratory:  (1)  drum,  (2)  drop,  and  (3)  com- 

1See  page  43. 

87 


WOODEN   BOX   AND    CRATE   CONSTRUCTION 


FIG.  23 — Testing    boxes    in    small    revolving    drum    developed    at    Forest 
Products  Laboratory. 


BOX  AND  CRATE  TESTING  89 


FIG.  24 — Standard    large    drum    testing    machine    developed    at    Forest 
Products   Laboratory. 


90  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


FIG.  25 — Method  of  making  drop-cornerwise  test 
A.     Releasing  device,  or  trip.        B.     Cast  iron  plate. 


BOX  AND  CRATE  TESTING  91 

pression.  Drop  tests  may  be  made  cornerwise  or  edgewise 
of  the  box ;  compression  tests  are  made  on  the  edges,  corners, 
or  faces.  In  general,  all  these  tests  lead  to  the  same  conclu- 
sions; the  one  selected  in  any  particular  case,  however,  will 
depend  on  the  hazards  to  which  the  containers  under  consid- 
eration are  subjected  in  transit. 

DRUM  TEST 

The  revolving  drum  type  of  box  testing  machine  illus- 
trated in  figures  23  and  24  is  an  approved  and  very  practical 
method  of  testing  boxes  and  crates.'  A  vertical  section  of  the 
drum  at  right  angles  to  the  axis  is  hexagonal  in  shape,  which 
gives  it  six  faces.  Upon  these  six  faces,  hazards  and  guides  are 
arranged  in  such  a  manner  that,  as  the  drum  revolves,  the  box 
or  crate  slides  and  falls  striking  on  ends,  sides,  top,  bottom, 
edges,  and  corners  in  such  ways  that  the  stresses,  shocks,  and 
rough  handling  of  actual  transportation  conditions  are  simu- 
lated. For  this  method  of  testing  the  box  or  crate  must  be 
loaded  with  its  contents  or  a  substitute  which  produces  the 
same  effect. 

The  six  faces,  cleats,  and  edges  of  a  box,  numbered 
for  testing  in  a  revolving  drum  are  shown  in  figures  3  and  4, 
Plate  XIV ;  and  the  corners  of  a  crate  and  other  parts  as  num- 
bered are  shown  by  figures  1  and  2,  Plate  XIV.  This  number- 
ing is  necessary  in  order  that  a  record  of  the  locations  and 
character  of  the  failures  may  be  made  as  they  occur.  As  the 
box  moves  on  from  one  drop  to  the  next,  the  observer  notes 
the  beginning  of  any  failure,  and  he  follows  the  progress  of 
that  and  any  other  failure  until  the  box  becomes  unserv- 
iceable. 

The  weak  feature  of  the  box  may  be  too  few  nails,  nails 
of  too  short  length,  nails  driven  in  a  crack  and  thus  having 
no  great  holding  power,  or  some  other  form  of  nail  weakness 
which  the  tests  will  clearly  show.  The  material  in  the  sides, 
top,  or  bottom  may  be  too  thin,  so  that  the  shocks  of  the 
falls  pull  the  wood  from  the  nails ;  the  wood  may  split  or 
break  across  the  grain. 

Any  one  of  the  numerous  weaknesses  of  packing  box 
construction  may  be  demonstrated  in  this  test,  which  enables 
the  observer  to  design  a  box  about  equally  serviceable  in 
every  feature,  or  balanced  in  construction.  Such  boxes  will 
show  failures  equally  likely  to  occur  in  nails  pulling  from 
the  wood,  wood  pulling  from  the  nails,  splitting  or  breaking 


92  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

of  ends,  sides,  tops  or  bottoms,  and  through  the  weaknesses 
of  the  wood  species. 

DROP  TESTS 

Drop-Cornerwise  Test — In  the  drop-cornerwise  test,  a  box 
or  crate  with  its  contents  is  suspended  by  each  of  its  corners 
alternately  and  dropped  from  a  definite  height  upon  a  cast  iron 
plate  or  other  solid  surface,  as  illustrated  in  figure  25.  This  is 
a  very  good  test  for  comparing  the  strength  of  various  types 
as  regards  their  ability  to  resist  this  particular  hazard  of  sud- 
den shock  and  distortive  action.  The  test  is  very  severe,  how- 
ever, and  several  failures  are  apt  to  occur  simultaneously,  so 
that  the  test  is  not  as  good  as  the  drum  test  for  drawing  con- 
clusions as  to  improvements  of  the  design. 

In  the  drop  test  the  corners  of  the  box  or  crate  where  the 
various  faces  meet  should  be  numbered  as  follows : 

Faces  Corner 

meeting  No. 

5-1-2  1 

6-3-4  2 

5-2-3  3 

6-1-4  4 

5-3-4  5 

6-1-2  6 

5-1-4  7 

6-2-3  8 

The  box  or  crate  should  then  be  dropped  on  the  corners 
in  numerical  rotation  and  then  the  cycle  repeated  until  failure 
occurs.  The  height  of  the  drop  is  usually  increased  for  each 
repetition  of  the  cycle. 

Drop-Edgewise  Test — The  drop-edgewise  test  is  similar 
to  the  drop-cornerwise  test  except  that  the  container  is 
dropped  on  an  edge  instead  of  a  corner,  being  suspended  from 
the  diagonally  opposite  edge. 

COMPRESSION  TESTS 

Compression-On-An-Edge  Test — In  the  test  illustrated 
by  figure  26,  a  compressive  force  is  exerted  over  the  whole 
length  of  one  edge  of  a  box  and  at  right  angles  to  it,  the  direc- 
tion of  the  force  also  passing  through  the  diagonally  opposite 
edge.  This  test  measures  the  ability  of  a  box  or  crate  to  resist 
being  collapsed  in  this  particular  manner  by  external  forces, 
enables  comparisons  to  be  made  of  the  relative  resistance  in 
containers  of  the  same  design,  and  provides  an  additional 
method  of  comparing  the  strength  of  containers  of  different 


BOX  AND  CRATE  TESTING 


93 


FIG.  26 — Method  of  making  compression-on-an-edge  test, 


94  WOODEN  BOX   AND    CRATE   CONSTRUCTION 


FIG.  27 — Method  of  making  compression-cornerwise  test. 


BOX  AND  CRATE  TESTING 


95 


F'IG.  28— Method  of  making  compression-on-faces   test. 


96  WOODEN  BOX   AND    CRATE   CONSTRUCTION 

designs.  This  test  is  usually  applied  to  the  empty  box  or  crate, 
although  it  may  be  applied  to  the  container  as  packed  for 
shipment. 

Compression-Cornerwise  Test — Another  compression  test, 
figure  27,  is  conducted  by  applying  compressive  forces  to  two 
corners  of  a  box  or  crate  and  directly  along  the  line  passing 
diagonally  through  those  corners  and  the  center  of  the  box  or 
crate.  The  general  purposes  of  such  a  test  are  similar  to  those 
given  for  the  preceding  test,  although  it  has  the  advantage  of 
more  readily  determining  the  weakest  elements  of  the  con- 
struction. Each  of  these  tests,  however,  brings  out  certain 
strength  factors  which  the  other  does  not,  so  that  one  can  not 
be  substituted  for  the  other. 

Compression-On-Faces  Test — A  test  which  subjects  a 
box  or  crate  to  the  stresses  that  it  encounters  when  support- 
ing heavy  static  loads  in  storage  warehouses  is  obtained  by 
direct  compression  at  right  angles  to  any  two  parallel  faces, 
as  illustrated  in  figure  28. 

SUPPLEMENTARY  TESTS 

In  addition  to  tests  on  completed  boxes  and  crates  there 
are  many  tests  that  will  give  much  information  of  value  to 
the  designer,  manufacturer,  and  user  of  boxes.  Among  these 
tests  are  the  following: 

1.  Mechanical-properties  tests  on  sawed  lumber,  rotary- 
cut  lumber,  and  plywood.     (See  page  26.) 

2.  Holding    power    of    nails,    screws,    bolts,    and    other 
fastenings. 

3.  Tensile   strength   tests  on  metal   strapping  and  wire 
ties  and  various  methods  of  fastening  them. 

4.  Density   determinations   for  woods   to   identify  weak 
and  brash  stock. 

5.  Determinations  of  the  percentage  of  moisture  in  wood. 

6.  Strength  tests  on  glued  joints. 

7.  Tests    on    the    strengthening    effects    of    corrugated 
fasteners. 

8.  Tests  on  special  materials  and  details,  such  as  rope, 
webbing  and  metal  handles,  hinges,  hoops,  locks,  etc. 

As  new  designs  of  containers  and  their  various  accesso- 
ries are  developed,  corresponding  tests  will  be  necessary  to 
determine  their  strength  and  advantages  as  compared  to  other 
containers  and  devices  of  a  similar  character. 


CHAPTER  V 
BOX   AND   CRATE   SPECIFICATIONS 

STANDARDIZATION  OF  PACKING  BOXES — NATIONAL  ASSOCIATION 
OF  Box  MANUFACTURERS'  TENTATIVE  GENERAL  SPECIFICA- 
TIONS FOR  NAILED  AND  LOCK  CORNER  BOXES — SPECIFIC 
SPECIFICATIONS  FOR  NAILED  AND  LOCK  CORNER  BOXES — 
GENERAL  SPECIFICATIONS  FOR  4-ONE  AND  SIMILAR  BOXES. 

Purpose — The  purpose  of  box  or  crate  specifications  is  to 
provide  that  part  of  a  contract  or  agreement  usually  made  be- 
tween a  box  manufacturer  and  his  customer  or  other  con- 
tracting parties  which  sets  forth  all  of  the  details  pertaining 
to  the  materials  used  and  the  construction  of  the  container 
as  they  are  to  be  furnished  or  executed  by  the  manufacturer. 
The  statements*  in  a  specification  should  be  definite,  concise, 
and  clear. 

The  specifications  for  a  box  or  crate,  so  far  as  they  affect 
its  actual  strength,  should  only  be  such  as  will  enable  the 
container  to  perform  satisfactory  service.  To  require  more 
than  this  will  usually  make  the  containers  less  economical. 

General  specifications  for  wooden  boxes  nailed  and  lock 
corner  are  given  below.  They  are  divided  into  four  parts, 
viz.,  material,  grouping  of  woods,  dimensions  of  parts,  and 
manufacture. 

These  general  specifications  are  intended  to  serve  as 
master  specifications  or  standards  of  construction  for  nailed 
and  lock-corner  boxes.  It  is  expected  that  specifications  for 
boxes  for  a  specific  commodity  or  group  of  commodities  will, 
as  they  are  worked  out  through  careful  research,  be  made  to 
conform  closely  to  these  general  specifications,  and  that  many 
of  their  requirements  will  be  specified  by  reference  to  the 
general  specifications.  It  will  be  necessary  to  add  only  such 
items  as  style  and  dimensions  of  box  and  minimum  thicknesses 
of  parts,  and  to  enumerate  such  exceptions  to  the  general 
specifications  as  may  be  found  necessary.  Many  points  must 
of  necessity  be  common  to  all  boxes  of  the  classes  under  con- 
sideration, and  brevity  is  gained  by  the  scheme  of  specifying 

97 


98  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

these   in   standards   for  boxes   for  a   specific   commodity   by 
reference. 

The  general  specifications  have  the  further  value  of  pro- 
viding a  much  needed  standard  as  a  guide  to  the  construction 
of  wooden  boxes.  The  principal  features  of  these  specifica- 
tions have  been  worked  out  from  a  large  number  of  careful 
tests  of  boxes  as  such,  and  from  very  extensive  data  on  the 
mechanical  properties  of  woods  as  determined  by  the  Forest 
Products  Laboratory. 

STANDARDIZATION    OF    PACKING    BOXES 

Paper   Presented   to    National  Association  of  Box  Manufac- 
turers in  Convention,  April,   1920 

"Standardization  of  packing  boxes  for  any  commodity,  like 
standardization  of  other  products,  tends  to  increase  produc- 
tion, to  insure  uniform  quality  and  to  lower  costs.  This  ap- 
plies not  only  to  uniformity  of  dimensions  of  the  box  and  its 
parts,  but  more  especially  to  all  those  specifications  of  quality 
which  directly  affect  the  strength  properties  of  the  package. 

"Processes  of  standardization  require  system  and  order 
first  of  all.  Haphazard  assembling  and  grouping  of  essential 
specifications  lead  to  duplications,  errors,  and  omissions  and 
tend  to  destroy  the  effectiveness  of  the  work.  No  attempt 
will  be  made  to  complete  this  project  before  distributing  the 
work.  Instead,  the  general  specifications  and  probably  sev- 
eral chapters  of  detailed  specifications  will  be  distributed  as 
compiled ;  succeeding  chapters  to  follow  as  they  are  com- 
pleted. It  is  advisable  that  those  who  receive  these  various 
installments  should  maintain  a  file  for  them. 

"This  project  of  standardization  for  nailed  and  lock  corner 
wooden  boxes  is  based  on  a  definite,  systematic  program, 
which  will  set  forth,  logically,  concisely  and  completely,  the 
best  that  can  be  compiled  by  this  association,  from  its  prac- 
tical experience,  combining  with  this  alt  that  has  been  de- 
veloped in  the  scientific  studies  by  trained  engineers  in  the 
laboratory. 

"As  in  all  other  types  or  kinds  of  packing  boxes,  certain 
fundamental  specifications  are  common  to  all  nailed  and  lock 
corner  wooden  boxes.  It  is  right  and  proper  that  these  funda- 
mentals be  stated  as  the  first  chapter  in  this  work  of  standard- 
ization. In  each  succeeding  chapter,  which  deals  with  the 
detailed  specifications  that  apply  to  its  particular  group  of 


BOX  AND  CRATE  SPECIFICATIONS  99 

boxes,  reference  will  be  made  to  the  general  specifications 
only  when  an  exception  is  to  be  made  in  the  interest  of 
greater  efficiency  or  lower  costs  of  production. 

"Each  chapter  or  bulletin  will  be  devoted  to  the  boxes  in 
common  use  for  one  general  class  of  commodities,  giving  the 
specific  thicknesses  of  material  to  be  used  for  those  particular 
boxes,  and  where  practicable  preferential  sizes,  together  with 
such  comments  and  notations  as  may  be  desirable  in  the  in- 
terest of  proper  packing. 

"In  compiling  these  specifications,  acknowledgment  is 
made  for  the  careful  and  comprehensive  work  of  the  U.  S. 
Forest  Products  Laboratory,  Madison,  Wis.,  and  for  the  co- 
operation of  those  leaders  in  the  box  making  industry  whose 
experience  has  been  drawn  upon  to  make  these  specifications 
thoroughly  practicable.  The  continued  work  of  research  will 
produce  new  and  greater  economies,  this,  with  changing  man- 
ufacturing and  commercial  conditions,  will  necessitate  fre- 
quent changes  in  standardized  box  construction  and  in 
specifications. 

"To  those  associations  of  shippers  and  to  those  in  trans- 
portation lines,  whose  activities  require  them  to  compile 
standard  of  box  construction,  whether  for  wooden  boxes  or 
for  any  of  the  other  types  or  kinds  of  containers,  this  method 
of  compiling,  (1)  the  general  .specifications  and  (2)  the  de- 
tailed specifications,  is  recommended  as  absolutely  necessary 
if  clear,  concise,  comprehensive,  efficient  and  economical  re- 
sults are  to  be  obtained. 

NATIONAL     ASSOCIATION     OF     BOX     MANUFACTURERS' 

TENTATIVE    GENERAL    SPECIFICATIONS    FOR 

NAILED  AND  LOCK  CORNER  BOXES1 

A.     MATERIAL 

Material — The  ends,  sides,  tops,  bottoms  and  other  parts 
of  wooden  boxes  must  be  well  manufactured  and  be  cut  true 
to  size.  All  defects  in  the  lumber  that  materially  lessen  the 
strength  of  the  part,  expose  contents  to  damage,  or  interfere 
with  proper  nailing,  must  be  eliminated.  The  lumber  must 
be  thoroughly  seasoned,  viz.,  have  an  average  moisture  con- 
tent of  12  to  18  per  cent,  based  on  the  weight  of  the  wood 
after  oven  drying  to  a  constant  weight. 

1Adopted    as    tentative    general    specifications    for    nailed    and    lock    corner    boxeq 
by  the  American  Society  of  Testing  Materials. 


ICO  WOODEN  BOX  AND  CRATE  CONSTRUCTION 

B.  GROUPING  OF  WOODS 

Grouping  of  Woods — The  principal  woods  used  for  boxes 

are  classed  for  the  purpose  of  specifications  in  four  groups : 

Group   I 

White  pine  Willow 

Norway  pine  Noble  fir 

Aspen  (popple)  Magnolia 

Spruce  Buckeye 

Western  (yellow)  pine  White  fir 

Cottonwood  Cedar 

Yellow  poplar  Redwood 

Balsam   fir  Butternut 

Chestnut  Cucumber 

Sugar  pine  Alpine  fir 

Cypress  Lodgepole  pine 

Basswood  Jack  pine 

Group   II 

Southern  yellow  pine  Douglas  fir 

Hemlock     .  Larch  (tamarack) 

North   Carolina  pine 

Group  III 

W7hite  elm  Black  ash 

Red  gum  Black  gum 

Sycamore  Tupelo 

Pumpkin  ash  Maple,  soft  or  silver 

Group  IV 

Hard  maple  Birch 

Beech  Rock  elm 

Oak  White  ash 

Hackberry  Hickory 

C.  THICKNESS  OF  LUMBER 

Thickness  of  Parts — The  thicknesses  called  for  in  specifica- 
tions for  boxes  of  any  given  commodity  will,  unless  otherwise 
stated,  be  understood  as  applying  to  Groups  I  and  II  woods. 
Where  the  material  is  specified  (for  Groups  I  and  II  woods) 
as  not  more  than  l/2  inch  thick  and  not  less  than  y%  irch, 
Groups  III  and  IV  woods  may  be  used  TV  inch  less  in  thick- 
ness; where  the  material  is  specified  (for  Groups  I  and  II 


BQX  AND   CRATE  SPECIFICATIONS  101 

woods)  as  more  than  y2  inch  thick  and  not  more  than  1  inch, 
Groups  III  and  IV  woods  may  be  used  l/s  inch  less  in  thick- 
ness;  where  the  material  is  specified  (for  Groups  I  and  II 
woods)  as  more  than  1  inch  thick  and  not  more  than  2  inches, 
Groups  III  and  IV  woods  may  be  used  ^  inch  less  in 
thickness. 

The  thickness  of  lumber  specified  allows  for  an  occa- 
sional unavoidable  variation,  but  that  variation  shall  not  ex- 
ceed one-eighth  of  the  thickness  of  the  part  below  the  thick- 
ness specified. 

D.     WIDTHS  OF  MATERIAL 

Widths  of  Parts — The  maximum  number  of  pieces  allowed 
in  any  side,  top,  bottom,  or  end  of  a  box  shall  be  as  follows : 

Width  of  face  Maximum  number  of  pieces 

5  inches  or  under  1 

Over     5  or  under     8  inches,  inclusive  2 

"       8   "       "       12      "  "  3 

"     12   "       "      20      "  "  4 

For  each  additional  5  inches  in  width  of  face,  one  addi- 
tional piece  may  be  used.  No  piece  less  than  2^  inches  face 
width  at  either  end  may  be  used  in  any  part,  except  for  cleats 
or  battens. 

E.     SURFACING 

Surfacing — The  outside  surfaces  of  boxes  must  be  suffi- 
ciently smooth  to  permit  of  legible  marking. 

F.     JOINING 

Joining — Ends  1  inch  or  less  in  thickness,  if  made  of  two 
or  more  pieces,  must  be  either  butt-jointed  or  matched,  then 
fastened  with  two  or  more  corrugated  fasteners  or  must  be 
cleated.  For  ends  %,  ^f,  and  ^  mcn  thick,  use  fasteners  1 
by  y%  inch  ;  for  ends  ^  inch  thick,  use  fasteners  1  by  V2  inch  ; 
for  ends  y2  and  T7^  inch  thick,  use  fasteners  1  by  %  inch.  Two 
or  more  pieces  Linderman  jointed  shall  be  considered  as  one 
piece. 

G.     SCHEDULE  OF  NAILING 

Size  of  Nails — All  nails  specified  are  standard  cement 
coated  box  nails.  (If  other  than  cement  coated  nails  are  used 
25  per  cent  more  nails  must  be  driven  than  specified).  Plain 
nails  driven  through  and  clinched  may  be  used  for  cleating. 


102 


£OX  AMD  'CRATE   CONSTRUCTION 


The  size  of  the  nail  to  be  used  shall  be  governed  by  the  species 
and  thickness  of  the  material  in.  which  the  points  of  the  nails 
are  held.  If  the  designated  penny  of  nail  is  not  available,  use 
the  next  lower  penny  and  space  nails  proportionately  closer. 
Nails  should  be  driven  flush — overdriving  materially  weakens 
the  container. 

NAILING  SCHEDULE 


Use  cement  coated 
nails  of  size 
indicated  when 
species  of  wood 
holding  nails  is 

Thickness  of  ends  or  cleats  to  which  sides, 
tops  and  bottoms  are  nailed 

Thickness  of  sides 
to  which  top  and 
bottom  are  nailed 

3/8 
or 
less 

7/16 

1/2 

9/16 

5/8 

11/16 
or 
3/4 

13/16 

8d 
7d 
7d 
6d 

7/8 

9d 

8d 
7d 
7d 

Less 
Than 

1/2 

4d 
4d 
3d 
3d 

1/2 
to 
9/16 

5/8 
to 
7/8 

Group     I  woods 
Group  II  woods 
GroupIII  woods 
Group  IV  woods 

4d 
4d 
3d 
3d 

5d 
4d 
4d 
3d 

5d 
5d 

4d 
4d 

6d 
5d 
5d 
4d 

7d 
6d 
5d 
4d 

8d 

7d 

6d 
5d 

6d 
5d 
4d 
4d 

7d 
6d 
5d 
5d 

H.     SPACING  OF  NAILS 

Spacing  of  Nails — In  order  to  ascertain  the  number  of 
nails  to  be  used,  divide  the  width  of  the  side,  top  and  bottom 
(or  length  of  cleat)  by  the  spacing  specified  for  the  gauge  of 
nails  to  be  used.  Fractions  in  the  result  greater  than  %  (if 
the  points  of  nails  are  to  be  held  in  the  end  grain)  and  greater 
than  y2  (if  the  points  of  nails  are  to  be  held  in  the  side  grain) 
will  be  considered  as  a  whole  number. 


When  nails  are 

6d   or   less    . 

7d    

8d    

9d    

lOd    . 


Space  when  driven  into 
Side  grain  of  end        End  grain  of  end 

2       inches  1$4  inches 

2V*       "  2 


No  board  shall  have  less  than  two  nails  at  each  nailing 
end.  Where  cleats  of  thickness  not  less  than  the  thickness  of 
the  ends  are  used,  approximately  50  per  cent  of  the  nails  will 
be  driven  into  the  cleats. 

Space  nails  holding  top  and  bottom  to  sides  six  to  eight 
inches  apart.  (When  material  in  sides  is  less  than  J/2  inch 
thick,  do  not  side  nail  unless  otherwise  specified.) 


BOX  AND   CRATE  SPECIFICATIONS 


103 


SPECIFIC    SPECIFICATIONS    FOR    NAILED    AND    LOCK 
CORNER  BOXES1 

The  following  are  specifications  for  Nailed  and  Lock 
Corner  boxes  for  carrying  specific  commodities,  minimum 
thickness  of  lumber  and  maximum  gross  weights: 

CANNED  FOOD  CASES 


Commodity 

Type  of 
box 
construc- 
tion 

Minimun 
material 
tions  of 
Groups  I 
eral  Spec 
parativi 
woods  in 

Ends 

i  thickness   of  the 
expressed  in  frac- 
an  inch,  woods  of 
and  II.     (See  Gen- 
ifications  for  com- 
j    thicknesses    of 
Groups  III  and  IV) 

Maxi- 
mum 
gross 
weight 
of  box 
and 
contents 

For  excep- 
tions to  gen- 
eral specifi- 
cations see 
reference  to 
notes  as 
numbered 

Sides 

Top  and 
bottom 

Canned  foods  in 
metal  cans,  viz.  : 
fish,  fruits,  meats, 
milk,  vegetables, 
other  foods  

Nailed  .  . 

5/8 
5/8 

5/16 

3/8 

5/16 

3/8 

90 
125 

Notes  1,  2 
Notes  1,2,  3 

Lock- 
corner  . 

7/16 

1/2 
5/8 

7/16 
5/16 
5/16 

5/16 
5/16 
5/16 

50 
50 
90 

Notes  1,  2 
Notes  1,  2 
Notes  1,  2 

NOTES  AND  EXCEPTIONS 

Note  i — When  one-piece  sides  and  two-piece  tops  and 
bottoms  of  Groups  I  and  II  woods  are  used,  material  may  be 
^V  inch  thinner  than  specified.  When  rotary  cut  gum  lumber 
is  used,  with  one-piece  sides  and  tops  and  not  more  than  two- 
piece  bottom,  the  thickness  may  be  fa  inch  less  than  speci- 
fied for  Group  III  woods,  minimum  thickness  l/4  inch. 

Note  2 — Inside  dimensions  of  boxes  shall  not  exceed  ^4 
inch  over  exact  length  and  width  and  y%  inch  over  exact 
depth  of  contents. 

Note  3 — Ends  must  be  cleated. 


GENERAL  SPECIFICATIONS  FOR  4-ONE  AND  SIMILAR 

BOXES 

The  following  specifications  are  substantially  those 
adopted  as  general  specifications  by  the  4-One  Association 
of  Box  Manufacturers,  and  as  tentative  general  specifications 
by  the  American  Society  for  Testing  Materials. 

aThe  foregoing  general  specifications  would  be  incomplete  without  an  illustra- 
tion of  their  application  to  a  specific  commodity.  Therefore,  specific  specifications 
for  canned  food  containers,  as  adopted  by  the  National  Association  of  Box  Manu- 
facturers, are  set  forth.  Specifications  for  boxes  for  other  commodities  have  been 
adopted,  but  will  not  be  incorporated  in  this  book. 


104 


WOODEN   BOX   AND    CRATE   CONSTRUCTION 


MATERIAL  COVERED 

1.  These  specifications  cover  three  styles  of  4-One  and 
similar  type  boxes  as  follows : 

(a)  General  form.. 

(b)  Boxes  with  wedgelock  ends. 

(c)  Boxes   with    detached    tops. 

2.  General  Form — (a)     The  boxes  knocked  down   shall 
,  consist  of  four   separate   sections   forming"   top,   side,  bottom, 

side,  connected  only  by  continuous  steel  binding  wires ;  and 
of  separate  ends. 

(b)  Each    of    the    separate    sections    forming   the    sides, 
top,   and   bottom    shall   consist   of   cleats,   thin   boards,   wires, 
and  staples. 

(c)  The   four   sections    shall   be    separated    such    a   dis- 
tance from  each  other  that  the  wires  shall  be  in  tension  at 
the  corners  when  the  sections  are  folded. 

3.  Grouping    of    Woods — For    the    purposes    of    these 
specifications,  box  lumber  shall  be  classed  into  four  groups 
as  follows: 


Alpin  fir 
Aspen   (popple) 
Balsam  fir 
Basswood 
Buckeye 
Butternut 
Cedar 
Chestnut 


Douglas   fir 

Hemlock 

Larch 

(tamarack) 


Group  I. 

Cottonwood 
Cucumber 
Cypress 
Jack  pine 
Lodgepole  pine 
Magnolia 
Noble   fir 
Norway   pine 

Group  II. 

Southern  yellow 
pine 


Group  III. 


Redwood 

Spruce 

Sugar  pine 

Western  yellow  pine 

White  fir 

White  pine 

Willow 

Yellow    poplar 


Virginia  and 
Carolina  pine 


Black  ash  Red   gum  Sycamore 

Black   gum  Red  gum  sap  wood  Tupelo 

Maple,  soft  or  silver      (commonly  W7hite  elm 
Pumpkin   ash                  called  sap  gum) 


BOX  AND   CRATE  SPECIFICATIONS  105 

Group  IV. 

Beech  Hickory  Rock  elm 

Birch  Maple,  hard  White  ash 

Hackberry  Oak 

MATERIALS 

4.  Cleats — (a)      Each    cleat  shall   be   sound,    free   from 
knots   and   from   cross   grain   which   runs   across   it   within   a 
distance  equal  to  one-half  its  length. 

(b)  Cleats  shall  be  not  less  than  }£  inch  thick  (paral- 
lel to  the  length  of  the  box)  and  not  less  than  %  inch  in 
width. 

5.  Thin  Boards — (a)      The  thin  boards  shall   be  sound 
(free  from  decay  and  dote),  well  seasoned  and  cut  so  that  ad- 
jacent faces  of  boxes  will  be  at  right  angles  to  each  other. 
All  defects  that  would  materially  lessen  the  strength,  expose 
the  contents  of  the  boxes  to  damage,  or  interfere  with  the 
proper  assembly  of  the  boxes  shall  be  eliminated. 

(b)  When  the  thickness  of  thin  boards  as  specified  is 
less  than  f\  inch,  thin  boards  made  of  woods  of  Groups  III 
and  IV  may  be  -fa  inch  less  than  the  specified  thickness  ex- 
cept that  the  minimum  thickness  of  thin  boards  of  any  kind  of 
wood  shall  be   J/s  inch. 

(c)  The  variation  in  thickness  of  thin  boards  below  the 
thickness  specified, shall  be  not  more  than  Vs  of  the  thickness 
of   the    thin    board,    and    this    variation    below    the    specified 
thickness  shall  not  extend  to  more  than    10  per  cent  of  the 

.face  of  that  particular  board. 

(d)  Thin  boards  less  than  2*/2  inches  in  width  at  either 
end  shall  not  be  used. 

6.  Staples — The  binding  wires   shall   be   annealed   steel 
wire  of  not  less  than  No.  16  gauge. 

7.  (a)     The  staples  on  end  wires  shall  be  not  less  than 
No.  16  gauge  by  lT/s  inches  long. 

(b)  Staples  on  intermediate  wires  shall  be  not  less  than 
No.  18  gauge  by  -f^  inch  long. 

ASSEMBLING 

8.  (a)     The  staples  on  end  wires  shall  be  driven  home 
astride  the  binding  wires,  through  the  thin  boards  into  the 
cleats,  and  anchored  in  the  cleats. 

(b)      The    staples    on    the    intermediate    wires    shall    be 


106  WOODEN   BOX   AND    CRATE,  CONSTRUCTION 

driven    astride    the   binding   wires,    through    the    thin    boards 
and  firmly  clinched. 

(c)  The  space  between  staples  shall  be  the  average  dis- 
tance between   centers  of  staples  astride   each  binding  wire 
in  each   section   and  this   space   shall  be  not  more  than  2l/2 
inches  except  as  specified  in  paragraph   (d). 

(d)  When  cleats  are  made  of  woods  of  Groups  III  and 
IV  the   space   between   the   staples   may   be   J/J    inch   greater 
than   that   specified. 

(e)  There    shall   be    not    less   than    two    staples  .driven 
astride  each  wire  and  into  each  thin  board. 

(f)  The  staples  nearest  the  corners   shall  be  not  more 
than  1^4  inches  from  the  corner  to  which  it  is  adjacent. 

9.  Each  end  of  the  box  shall  be  securely  fastened  on  the 
inside  of  the   side   cleats  with   staples  not  less  than   No.   16 
gauge  by  -Jf  inch  long,  or  with   cement-coated  nails  of  not 
less  than  two-penny  size.     There  shall  be  no  space  exceeding 
2l/2  inches  on  any  side  cleat  into  which  no  staple  or  nail  hold- 
ing the  end  in   place  has  been  driven   and  there  shall  be   a 
staple  or  nail  within  \l/2  inches  of  each  end  of  each  side  cleat. 
Staples  or  nails  shall  be  driven  home. 

10.  At  each  corner  one  section  shall  overlap  its  adjacent 
section  at  right  angles  and  the  wire  shall  be  in  tension,  giv- 
ing a  square,  tight  corner. 

11.  The  cover  shall  be  closed  tightly  and  the  ends  of 
each    binding    wire    twisted    tightly    together.      The    twisted 
portion  of  each  wire  shall  be  not  less  than  y2  inch  long.    The 
rough  ends  of  the  wires  shall  be  removed  and  the  twisted 
portion  driven  flat  against  the  side  parallel  with  the  binding 
wire. 

12.  Nothing  herein  contained  shall  be  construed  as  pro- 
hibiting the  use  of  boxes  constructed  of  thicker  thin  boards, 
additional    or    heavier   wires,    heavier    cleats,    longer    staples, 
or  with  closer  spacing  of  staples. 

13.  Boxes    with    Wedgelock    Ends— These    boxes    shall 
consist  of  sides,  top,  and  bottom  and  one   end  made  in  ac- 
cordance with  sections  2-12  inclusive,  pages  104  to  106,  inclu- 
sive, and  of  one  wedgelock  end. 

14.  Wedgelock  ends  shall  consist  of  the  following: 

(a)  One  or  more  thin  boards  whose  thickness  is  not  less 
than  that  of  the  thin  boards  in  the  other  portions  of  the  box 
and  whose  combined  width  is  y%  inch  less  than  the  shortest 
distance  between  the  top  and  bottom  cleats  of  the  box  and 


BOX  AND   CRATE  SPECIFICATIONS  107 

whose  length  is  the  same  as  the  inside  width  of  the  box  less 
the  width  of  one  of  the  side  cleats. 

(b)  Two  battens  of  the   same  thickness  and  width  as 
the  cleats  in  the  box  and  whose  length  is  ^  inch  less  than  the 
shortest  distance  between  the  top  and  bottom  cleats. 

(c)  One   wedge   of   the    same   thickness   and   length   as 
the  battens  and  whose  wridth  is  one-half  that  of  the  battens. 

15.  The  battens  shall  be  attached  across  the  grain  of  the 
thin  boards,  one  batten  its  own  width  from  one  end  and  the 
other  batten   half  its  width  from  the  other  end  of  the  thin 
boards,  with  staples  not  less  than  No.  16  gauge  by  ^f  inch 
long  or  with  nails  not  less  than  two-penny  size.     There  shall 
be  no  space  exceeding  2  inches  on  any  batten  into  which  no 
staple  or  nail  holding  the  thin  boards  to  the  batten  has  been 
driven  and  there  shall  be  a  staple  or  nail  within  \y>  inches  of 
each   end  of  each  batten.     Staples  or   nails   shall  be   driven 
home. 

In  making  up  the  box,  the  wedgelock  end  is  left  out  so 
that  the  box  may  be  filled  from  the  end.  The  other  end  of  the 
box  is  fastened  in  place  and  the  box  made  up  as  specified  in 
sections  9-11,  page  106.  The  wedgelock  end  is  not  fastened  in 
place  until  the  box  is  closed. 

Boxes  with  wedgelock  ends  are  closed  as  follows : 
The  wedgelock  end  is  inserted.  The  wedge  is  inserted, 
the  batten  that  rests  against  the  wedge  is  fastened  to  the 
wedge  with  one  four-penny  nail  driven  through  the  middle 
of  the  batten  into  the  wedge.  The  other  batten  that  rests 
against  the  cleat  is  fastened  to  that  cleat  with  four-penny 
nails  driven  through  the  batten  into  the  cleat.  Nail  centers 
shall  be  not  more  than  4  inches  apart,  and  there  shall  be  a 
nail  within  at  least  2  inches  of  each  end  of  this  batten. 

16.  Boxes  with  Detached  Tops — These  boxes  shall  con- 
sist of  sides,  bottom  and  ends  made  in  accordance  with  sec- 
tions 2-12  inclusive,  pages  104  to  106,  and  a  detached  top  made 
of  thin  boards. 

17.'  In  assembling  the  box,  the  top  cleats  to  which  the 
binding  wires  have  been  stapled  shall  be  put  in  position  on 
the  side  cleats  and  the  ends  of  each  wire  stapled  to  the  cleats 
twisted  tightly  together. 

The  detached  top  shall  be  nailed  to  the  end  cleats  with 
cement-coated  box  nails  spaced  not  more  than  2l/2  inches 
apart.  The  wires  not  stapled  to  the  cleats  shall  be  brought 
over  the  detached  top  and  the  ends  of  each  wire  twisted 
tightly  together. 


CHAPTER  VI 
STRUCTURE   AND   IDENTIFICATION   OF  WOODS 

STRUCTURE  OF  WOOD — PROCEDURE  IN  IDENTIFYING  WOOD — KEY 
FOR  THE  IDENTIFICATION  OF  WOODS  USED  FOR  Box  AND 
CRATE  CONSTRUCTION — DESCRIPTION  OF  Box  WOOD — GRAD- 
ING RULES  FOR  ROTARY-CUT  LUMBER. 

More  than  forty  different  species  of  wood  are  used  in 
box  construction.  It  is  essential  to  be  able  to  distinguish 
these  woods  in  order  that  they  may  be  used  intelligently.  For 
instance,  it  is  necessary  to  be  able  to  classify  the  commercial 
woods  used  for  boxes  into  the  four  groups  outlined  in  the 
specifications  for  boxes  and  crates,  (See  grouped  list,  Part  V, 
page  100.)  Such  properties  as  color,  odor,  taste  and  weight  are 
very  helpful  in  placing  any  given  wood  in  the  group  where  it 
belongs;  information  as  to  the  section  of  the  country  from 
which  the  wood  was  obtained  is  also  of  assistance ;  but  some 
knowledge  of  structure  is  indispensable  for  accurately  making 
the  required  distinctions.  When  a  wood  is  dry  it  may  lose 
much  of  the  odor  that  distinguished  it  when  green ;  if  it  is 
stained,  weathered,  or  artificially  treated,  any  characteristic 
color  may  not  be  apparent;  its  weight,  too,  when  it  is  green 
(saturated  with  moisture),  when  partly  seasoned,  and  when 
kiln-dried  is  very  different ;  under  all  these  conditions,  how- 
ever, the  structure  is  practically  unchanged  and,  therefore, 
serves  as  an  unfailing  guide  in  identifying  the  wood.  More- 
over, accurate  descriptions  of  characteristic  structures  are 
possible,  whereas  descriptions  of  color  and  so-called  "grain" 
are  difficult  to  put  into  words  and  are  open  to  wrong  inter- 
pretation because  of  the  variation  of  individual  opinions  and 
observations  on  "grain"  and  color. 

The  identification  of  woods  as  described  in  the  following 
pages,  therefore,  is  based  primarily  on  the  structure  of  the 
wood,  but  is  supplemented  by  such  other  physical  properties 
as  are  helpful  in  distinguishing  the  different  species  or  groups 
of  woods. 

108 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS        109 

STRUCTURE    OF    WOOD 
HEARTWOOD  AND  SAPWOOD 

In  mature  trees  two  portions  of  the  wood  of  the  trunk 
are  generally  to  be  distinguished.  These  are  the  sapwood  and 
the  heartwood.  The  sapwood  is  found  next  to  the  bark ;  it  is 
generally  light  colored  and  varies  only  slightly  in  shade.  It 
varies  considerably,  however,  in  width.  In  some  species  it  is 
less  than  an  inch  wide,  as,  for  example,  in  arborvitse,  western 
red  cedar,  black  ash,  and  slippery  elm.  On  the  other  hand,  in 
other  species,  such  as  maple,  birch,  hickory,  white  ash,  green 
ash,  hackberry,  and  some  hard  pines,  it  is  several  inches  in 
width.  Besides  the  variations  in  sapwood  in  species,  the  width 
of  sapwood  may  also  vary  within  the  same  tree  or  species, 
depending  upon  the  age,  vigor  of  grdwth,  and  height  above 
the  ground  of  the  individual  specimen.  The  sapwood  con- 
tains living  cells  and  it  is  through  this  portion  of  the  woody 
cylinder  that  the  sap  circulates  in  the  tree. 

The  heartwood  is  dead  so  far  as  the  life  processes  of  the 
tree  are  concerned.  The  heartwood  was  once  sapwood.  After 
serving  for  sap  conduction  and  other  growth  activities  for  a 
number  of  years  the  sapwood  gradually,  often  without  any 
sharp  line  of  demarkation,  changes  into  heartwood  and  ceases 
to  function  in  the  life  of  the  tree  except  for  the  fact  that  it 
gives  mechanical  support  to  the  crown,  thus  helping  hold  the 
leaves  up  in  the  sunlight.  The  change  from  sapwood  to  heart- 
wood  is  very  often,  but  not  always,  accompanied  by  a  change 
in  color.  Some  woods  in  which  the  change  in  color  is  lack- 
ing or  very  slight  are  white  and  red  spruce,  hemlock,  Port 
Orford  cedar,  basswood,  white  cottonwood,  aspen  or  "popple," 
buckeye,  "whiteheart"  beech1,  and  hackberry.  The  color  of 
the  heartwood,  when  markedly  different  from  that  of  the  sap- 
wood,  is  of  great  assistance  in  identifying  different  species  of 
wood,  such  as  red  gum,  yellow  poplar,  and  black  ash. 

The  structure  of  the  sapwood  and  the  heartwood  is  the 
same  except  for  the  fact  that  the  pores  or  large  tube-like  cells 
of  the  heartwood  of  some  hardwoods  are  frequently  more  or 
less  closed  with  cell-like  growths  called  tyloses  or  with 
gummy  substances.  In  the  sapwood,  especially  in  the  outer 
sapwood  next  the  bark,  the  pores  are  open  and  serve  to  con- 
duct sap.  Sometimes  the  sapwood  of  lumber  becomes  much 
discolored,  blued,  or  darkened,  through  the  presence  of  sap- 

1Some   beech   has    a   very   reddish   heartwood   frequently   with    different   properties 
from   the    "whiteheart"    beech—this   is    often   called    "redheart"    beech. 


110  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

stain  fungi.  Some  woods  in  which  the  sapwood  is  often  blued 
or  otherwise  stained  are  pines,  spruces,  red  gum,  and  hack- 
berry.  In  hackberry  the  stained  sapwood  often  appears  darker 
in  color  than  the  heartwood.  Discoloration  may  also  be  pro- 
duced by  chemical  changes  in  the  wood  without  the  action 
of  fungi ;  for  example,  brown  stain  in  sugar  pine  or  the  colors 
produced  by  the  contact  of  the  saw  with  the  substances  in  oak. 

ANNUAL  RINGS 

Annual  rings  are  the  more  or  less  w7ell  denned  concentric 
layers  of  wood  laid  down  each  year  by  the  growing  tree.  They 
are  particularly  noticeable  on  the  stump  of  a  tree  or  on  any 
cross  section  of  the  wood.  Annual  rings  are  more  conspicu- 
ous in  oak,  elm,  and  ash,  or  pine  and  fir  than  they  are  in  woods 
like  "popple"  or  aspen,  buckeye,  cottonwood,  tupelo,  and  wil- 
low. Many  woods  grown  in  the  tropics  do  not  show  well 
defined  annual  rings,  although  they  may  show  zones  of  growth 
due  to  changes,  often  not  annual  but  produced  by  climatic 
conditions  other  than  the  summer  and  winter  changes  of  tem- 
perate climates. 

The  appearance  of  the  annual  rings  on  a  smoothly-cut 
cross  section  is  of  great  assistance  in  identifying  woods. 

SPRINGWOOD  AND  SUMMERWOOD 

The  springwood  is  that  part  of  the  annual  ring  which  is 
first  formed  each  year.  The  wood  is  usually  lighter  in  weight 
and  softer  because  it  contains  more  air  spaces,  that  is,  larger 
cell  cavities  and  less  wood  substance  than  that  formed  later 
on  in  the  year.  As  the  season  advances  the  cell  walls  formed 
are  usually  thicker  and  the  cavities  smaller  so  that  the  growth 
which  is  called  summerwood  is  denser,  harder,  and  often 
darker  in  color  than  the  springwood.  In  some  woods,  such  as 
maple,  birch,  and  basswood,  there  is  a  little  difference  between 
the  springwood  and  summerwood.  In  the  case  of  spruce  or 
hemlock  the  change  from  springwood  to  summerwood  is  grad- 
ual, but  in  oak  and  longleaf  pine,  for  instance,  the  difference 
between  springwood  and  summerwood  is  not  only  marked 
but  the  change  is  very  abrupt.  It  is  often  possible  to  estimate 
the  strength  of  wood  by  noting  the  percentage  and  density  of 
the  summerwood. 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS         111 


FIG.  29 — Section  of  western  yellow  pine  log  showing:  -radial   surface,   R; 
tangential  surface,  T ;  heartwood,  H  ;  sapwood,  S ;  pith,  P.    The  annual 
rings  are  the  concentric  layers  widest  near  pith  and  usually  becoming  nar- 
rower toward  the  bark.   The  summerwood  produces  the  dark  lines  that 
stand  out  conspicuously  on  both  the  radial  and  tangential  surfaces. 


112  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

THE  STRUCTURE  OF  HARDWOODS 

The  name  "hardwood"  applies  chiefly  to  woods  which  are 
characteristically  hard  and  strong,  such  as  oak,  hickory  and 
ash.  The  hardwood  group,  however,  includes  some  woods 
which  are  not  relatively  very  hard,  as,  for  instance,  basswood 
and  "popple."  The  real  distinction  on  which  the  grouping 
into  hardwoods  and  softwoods  is  based  is  not  the  hardness 
but  the  structure  of  the  wood. 

All  the  commercial  hardwoods  of  the  United  States  con- 
tain pores  or  vessels,  cells  which  are  strikingly  larger  than  the 
other  cells  with  which  they  are  associated.  The  conifers  or 
softwoods  do  not  have  these  pores  or  vessels.  They  are  often 
called  non-porous  woods.  Some  of  them,  for  example  south- 
ern yellow  pine  or  Douglas  fir,  may  be  actually  harder  than 
such  hardwoods  as  basswood.  The  hardwoods,  for  the  most 
part,  come  from  broad-leaved  trees,  such  as  maple,  elm,  and 
poplar,  and  the  softwoods  from  needle  or  scale-leaved  trees 
like  pines  or  cedars. 

All  hardwoods  have  pores.  In  many  cases  pores  are 
visible  to  the  naked  eye.  They  appear  on  a  smoothly-cut 
cross  section  as  more  or  less  circular  openings.  On  a  longi- 
tudinal section  they  appear  like  fine,  more  or  less  interrupted 
grooves  and  may  be  used  to  determine  the  direction  of  the 
grain,  as,  for  example,  cross  or  spiral  grain.  Where  they  are 
not  visible  to  the  naked  eye  they  may  be  seen  with  the  aid  of 
a  magnifying  glass  with  an  enlarging  power  of  about  12  to  18 
diameters.  The  group,  however,  may  be  divided  into  two 
classes  according  to  the  arrangement  of  these  pores.  When 
the  large  pores  are  grouped  conspicuously  at  the  beginning  of 
each  annual  ring  and  there  is  an  abrupt  change  in  size  from 
the  springwood  to  the  summerwood  pores  the  woods  are 
called  ring-porous.  The  springwood  pores  are  usually  visible 
to  the  naked  eye  in  this  type  of  wood.  Examples  of  ring- 
porous  woods  are  oak,  ash,  elm,  hickory,  and  locust.  In  this 
type  of  wood  the  annual  rings  are  distinctly  defined. 

If,  on  the  other  hand,  the  pores  are  scattered  with  con- 
siderable uniformity  throughout  the  ring  and  the  change  in 
the  size  of  the  pores  from  the  inner  to  the  outer  portion 
(spring  to  the  summerwood)  is  slight  or  gradual,  the  woods 
are  called  diffuse-porous.  Examples  of  woods  of  this  sort  are 
maple,  birch,  tulip,  gum,  sycamore,  and  willow. 

Tyloses  are  cell-like  growths  which  often  appear  like  a 


STRUCTURE  AND  IDENTIFICATION   OF   WOODS        113 

froth  or  a  number  of  glistening  particles  in  the  pores  of  the 
hardwoods.  They  are  especially  conspicuous  in  such  woods 
as  hickory  and  most  of  the  white  oaks.  Tyloses,  when  pres- 
ent, are  found  in  the  inner  sapwood  and  the  heartwood.  The 
outer  sapwood  pores  are  normally  open.  The  presence  of 
tyloses  is  often  of  assistance  in  identifying  woods.  White 
oak  with  an  abundance  of  tyloses,  for  instance,  is  used  for 
tight  cooperage  (barrels  to  contain  liquids),  while  red  oak, 
which  generally  (not  always)  lacks  tyloses,  is  not  as  suitable 
for  liquid  containers  and  is  used  for  slack  cooperage  (barrels 
for  dry  materials  such  as  cement  or  flour). 

Lines  of  light  colored  tissue  extending  out  from  the  pores 
may  be  seen  on  the  smoothly-cut  cross  section  of  such  woods 
as  white,  green,  or  pumpkin  ash.  These  lines  are  of  consider- 
able assistance  in  identifying  these  woods.  They  are  com- 
posed of  small  rather  thin-walled  cells  which  may  easily  be 
crushed  when  a  section  is  cut.  These  cells  are  known  as 
parenchyma  tissue. 

Rays  (often  called  medullary  rays)  are  more  or  less  nar- 
row strips  of  cells  which  extend  from  the  bark  towards  the 
center  of  the  tree.  They  run  horizontally  at  right  angles  to 
the  vertical  grain  of  the  wood.  They  may  be  compared  to 
minute  two-edged  swords  thrust  from  the  inner  bark  toward 
the  heart  of  the  tree.  On  the  end  surface  they  appear  as  lines, 
crossing  the  annual  rings,  like  the  radii  of  a  circle  or  the 
spokes  of  a  wheel,  although  all  the  rays  do  not  originate  at 
the  center  of  the  tree.  The  rays  are  very  large  and  conspicu- 
ous in  oaks,  in  which  they  are  sometimes  said  to  produce 
"silver  grain"  or  "fleck."  The  rays  are  also  easily  seen  with 
the  naked  eye  in  sycamore  and  beech.  Although  they  are 
visible  in  all  woods  on  truly  radial  surfaces,  especially  on 
split  surfaces,  and  in  many  woods  on  the  end  surface  there 
are  also  a  considerable  number  of  species  in  which  they  can- 
not be  seen  on  the  end  surface  with  the  naked  eye.  Quarter- 
sawed  or  edge-grain  material  is  produced  by  cutting  through 
the  center  of  the  tree  approximately  parallel  to  these  rays 
(radial  cut).  Flat-grained,  slab,  or  plain-sawed  material  is 
cut  at  right  angles  to  the  rays  (tangential  cut). 

Wood  fibers  are  the  small  cells  which  make  up  the  greater 
part  of  the  dense  wood  substance  between  the  pores  and  the 
rays  of  hardwoods.  They  are  thick-walled  and  too  small  to 
be  seen  individually  without  considerable  magnification.  Col- 


114  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

lectively,  they  are  seen  to  form  the  darker,  denser  portions 
which  give  most  of  the  weight  and  strength  to  the  wood. 

Pith  flecks  are  small  dark  spots  or  streaks  which  occur 
characteristically  in  certain  woods,  as,  for  example,  soft  maple 
and  river  birch. 

THE  STRUCTURE  OF  CONIFERS 

In  conifers  or  softwoods  the  rays  and  the  fiber-like  cells 
(tracheids)  make  up  the  wood.  The  tracheids  serve  the  com- 
bined purpose  of  the  pores  and  the  wood  fibers  of  the  hard- 
woods, that  is,  they  support  the  tree  and  assist  in  the  con- 
duction of  the  sap.  The  truth  of  the  statement  that  wood 
resembles  a  honeycomb  is  strikingly  evident  when  the  struc- 
ture of  a  softwood  is  examined  under  a  lens.  In  the  wood  the 
cells  are,  in  proportion  to  their  width,  longer  than  they  are 
in  the  honeycomb,  although  they  are  rarely  over  l/$  inch  in 
length.  The  resemblance  is  due  to  the  regularity  of  arrange- 
ment of  the  cells,  which  are  of  approximately  uniform  width 
tangentially  and  are  arranged  in  very  regular  radial  rows,  as 
is  apparent  in  the  pictures  of  conifer  cross  sections.  (See 
figure  2,  Plate  II.)  Because  the  conifers  do  not  have 
cells  which  are  strikingly  larger  than  the  other  cells  (pores) 
they  are  called  non-porous  woods  or  woods  without  pores. 
(It  should  be  noted  that  the  word  "porous"  as  applied  to  sub- 
stances like  a  sponge,  which  contain  empty  spaces  and  may 
absorb  liquids,  may  be  applied  also  to  both  softwoods  and 
hardwoods  which,  of  course,  contain  air  spaces ;  but  the  word 
"pore"  or  "vessel"  is  used  in  the  classification  of  hardwoods 
and  conifers  in  a  different  sense  when  reference  is  made  to 
the  presence  of  a  definite  type  of  cell  in  the  hardwoods  or 
"porous"  woods.) 

In  the  softwoods  the  annual  rings  are  usually  very  clearly 
defined  (more  clearly  than  in  some  diffuse-porous  woods) 
because  toward  the  close  of  the  growing  season  the  cells  be- 
come thicker  walled  and  are  flattened  somewhat  radially,  thus 
producing  the  distinctive  summerwood  of  the  annual  rings. 

The  rays  in  the  conifers,  although  present,  are  so  small 
as  to  be  invisible  on  the  end  surface  without  a  lens.  They 
are  very  numerous,  however,  as  many  as  fifteen  thousand  to 
the  square  inch  (21  to  27  per  square  mm.)  of  tangential  sur- 
face have  been  noted  in  such  a  wood  as  pine.1 

1U.     S.     Department    of    Agriculture,     Division     of     Forestry,     Bulletin     13.      The 
Timber    Pines    of   the    Southern    U.    S.,    page    152. 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS        115 

Resin  passages  or  ducts  are  found  in  four  genera  of  the 
conifers,  namely,  in  pines,  spruces,  Douglas  fir,  and  larch  or 
tamarack.  Resin  ducts  are  openings  which  have  been  pro- 
duced when  the  cells  of  the  wood  have  split  apart,  that  is, 
they  are  intercellular  spaces.  These  passages  or  ducts  extend 
both  vertically  and  horizontally  in  the  tree.  The  vertical 
ducts  in  the  woods  mentioned  usually  occur  in  or  near  the 
summerwood  and  are  more  visible  than  the  horizontal  ducts 
which  are  found  in  some  of  the  rays  (fusiform  rays).  These 
latter  may  be  seen  as  very  minute  dark  specks  on  the  tan- 
gential surface  of  the  woods  of  the  species  just  mentioned. 
Resin  is  stored  in  these  ducts  or  intercellular  spaces  and  often 
gives  them  a  brownish  or  amber  color  which  assists  in  their 
detection,  especially  on  longitudinal  surfaces.  The  ducts, 
especially  the  vertical  ones,  are  most  conspicuous  in  pines. 
When  a  very  smoothly-cut  end-grain  surface  is  examined  the 
vertical  resin  ducts  are  barely  visible  to  the  naked  eye  as 
minute  dots  in  or  near  the  summerwood.  In  spruces,  larches, 
and  Douglas  fir  the  resin  ducts  are  usually  smaller  and  less 
numerous  than  in  pines,  and  they  are  sometimes  found  in 
short  tangential  rows.  The  direction  of  the  grain,  especially 
spiral  grain,  may  be  determined  by  observing  the  vertical 
resin  ducts  which  run  parallel  with  the  fibers.  Exudation  of 
resin  sometimes  occurs  from  the  ducts  on  the  ends  of  pieces 
of  these  four  kinds  of  woods.  The  absence  of  such  exuda- 
tions of  resin  does  not  necessarily  mean  that  resin  ducts  are 
not  present,  for,  as  a  rule,  the  resin  does  not  exude  from  the 
ducts  in  seasoned  wood  unless  the  wood  is  heated.  In  woods 
in  which  resin  ducts  are  present  pitch  pockets  or  pitch  streaks 
may  also  be  found.  Such  coniferous  woods  as  cedars,  cypress, 
redwood,  and  balsam  firs  do  not  normally  have  resin  ducts. 
They  may,  however,  contain  some  resinous  material  in  their 
rays  or  in  certain  scattered  cells. 

PROCEDURE    IN    IDENTIFYING    WOOD 

If  color,  odor,  weight,  or  general  appearance  is  not  suffi- 
ciently distinctive  to  identify  a  specimen  of  wood,  an  examina- 
tion of  the  more  detailed  structure  should  be  made.  In  the 
key  which  follows,  the  somewhat  similar  woods  are  syste- 
matically grouped  together  and  the  characteristic  distinctions 
by  which  they  can  be  separated  are  given  to  assist  in  rapid 
and  accurate  identification.  Photographs  showing  a  slightly 


116  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

magnified  cross  section  of  the  different  species  are  also  given. 
These  show  very  clearly  the  distinctions  which  may  usually 
also  be  seen  with  the  naked  eye  on  a  smoothly-cut  surface  of 
the  end  grain  of  the  wood.  Contrary  to  common  practice, 
it  is  the  cross  section  or  end  grain,  which,  when  smoothed  off, 
with  a  very  sharp  knife,  usually  presents  the  best  surface 
from  which  to  make  an  identification ;  for,  in  general,  it  is 
here  rather  than  on  the  longitudinal  surface  that  the  prin- 
cipal distinctive  characteristics  in  a  difficult  identification  are 
to  be  found.  The  need  of  a  very  sharp  knife  and  smoothly- 
cut  surface  cannot  be  too  strongly  emphasized.  With  a  dull 
knife  scratches  and  other  irregularities  may  be  produced 
which  are  sometimes  mistaken  for  structures. 

To  determine  the  color  of  a  wood  a  freshly-cut  longi- 
tudinal surface  of  the  heartwood  should  be  used,  since  ex- 
posed surfaces  may  become  weathered  or  soiled  so  that  the 
characteristic  color  is  changed.  Odor  and  taste  should  also 
be  determined  from  freshly-cut  surfaces,  shavings,  or  saw- 
dust, since  they  are  often  lost  if  the  material  is  exposed  to  the 
air  for  any  length  of  time. 

The  first  step  in  identifying  an  unknown  wood  is  to  de- 
termine whether  or  not  pores  are  present.  In  many  woods 
the  pores  are  readily  visible  to  the  naked  eye,  but  in  some 
they  are  difficult  to  see  or  invisible  without  magnification. 
This  is  particularly  true  in  certain  diffuse-porous  woods,  such 
as  sycamore,  beech,  red  gum,  maple,  yellow  poplar,  basswood, 
tupelo,  buckeye  and  aspen.  In  the  case  of  practically  all  of 
these  woods,  however,  there  are  characteristics  which  readily 
distinguish  them  from  the  somewhat  similar  appearing  soft- 
woods where  pores  are  lacking.  These  are,  for  instance,  the 
relatively  large  rays  found  in  beech,  sycamore,  maple,  and 
basswood,  the  color  of  the  heartwood  of  red  gum  and  yellow 
poplar,  and  the  lack  of  sharply-defined  annual  rings  in  tupelo, 
aspen,  and  buckeye,  together  with  other  details  which  are 
given  in  the  key,  thus  making  it  possible  readily  to  separate 
these  hardwoods  from  certain  of  the  softwoods  for  which  they 
might  be  mistaken. 

After  determining  whether  a  wood  is  a  hardwood  (with 
pores)  or  a  softwood  (without  pores),  the  next  step  is  to 
place  the  wood  under  one  of  the  sub-divisions  under  the  group 
to  which  it  belongs ;  that  is,  if  it  is  a  hardwood,  note  whether 
it  is  ring-porous  or  diffuse-porous.  Then  if  it  is  a  ring-porous 
wood,  note  whether  or  not  the  summerwood  is  figured  and, 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS        117 

if  so,  whether  the  figure  of  the  summerwood  runs  with  the 
rays  across  the  rings  (radial)  figures  1,  2,  and  3,  Plate  XVI, 
or  with  the  rings  (tangential),  figures  4,  5,  6,  7,  and  8,  Plate 
XVI. 

The  most  distinctive  features  within  the  diffuse-porous 
group  are  the  size  of  the  pores  and  the  size  of  the  rays,  the 
color  and  the  weight  of  the  wood. 

If,  on  the  other  hand,  the  wood  is  a  conifer  (without 
pores),  the  annual  rings  are  usually  well  defined  by  the  con- 
trast between  springwood  and  summerwood.  The  principal 
characteristics  in  this  group  are  odor,  presence  of  resin  ducts 
in  certain  woods,  color,  and  weight. 

It  is  not  to  be  expected  that  the  key  can  be  used  success- 
fully without  some  practice.  It  is  also  very  desirable  that 
the  person  who  is  to  make  a  specialty  of  wood  identification 
should  have  a  collection  of  known  samples  of  wood  which 
show  characteristic  color  and  structure  (that  is,  not  extremely 
fast  or  extremely  slow  growth)  for  comparison.  It  should  be 
noted  that  in  the  key  the  name  of  the  wood  follows  its 
description. 


KEY  FOR   THE  IDENTIFICATION   OF  WOODS   USED 

FOR  BOX   AND   CRATE  CONSTRUCTION1 

(without  the  aid  of  hand  lens) 

HARDWOODS 

Woods  from  broad-leaved  trees. 

Woods  with  pores  or  vessels,  that  is,  cells  larger  than 
those  surrounding  them. 

I.  Pores  present — (Sometimes  not  visible  to  the  naked  eye 
in  certain  diffuse-porous  woods,  in  which,  however,  the 
distinct  rays  or  lack  of  well-defined  summerwood  dis- 
tinguish them  from  conifers.) 

A.  Ring-porous  woods — The  comparatively  large  spring- 
wood  pores  are  clearly  visible,  especially  in  the 
sapwood  at  the  beginning  of  each  annual  ring.  On 
the  end  grain  of  a  log  these  pores  form  distinct 
rings.  The  marked  difference  between  springwood 

Unless  otherwise  stated  all  observations  of  structure  are  made  on  a  smoothly 
cut  cross  section  or  end  grain  showing  growth  rings  of  average  width.  A  sharp 
knife  is  indispensable.  All  color  determination  should  be  made  on  a  freshly-cut 
longitudinal  surface  of  the  heartwood.  See  pages  126  to  136  for  a  more  detailed 
discussion  of  each  wood. 


118  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

and  summerwood  is  characteristic.  Longitudinal 
surfaces  appear  coarse  textured  because  of  the 
large  springwood  pores  which  show  as  fine  grooves 
or  furrows,  often  producing  a  characteristic  figure. 
These  woods  are  mostly  heavy  and  are  found  in 
box  wood  groups  three  and  four.  Chestnut,  which 
is  a  ring-porous  wood,  is  an  exception ;  it  is  fairly 
light  when  seasoned  and  is  classified  in  group  one 
of  the  box  classification. 

1.  Summerwood  figured  with  wavy  or  branched  radial  bands. 

(Bands  extend  across  the  rings  in  the  same  direction  as 
the  rays.) 

(Compare  Plate  XVI,  figures  1  to  3.) 

AA.  Rays,  many,  broad,  and  conspicuous.  They  appear 
as  "flecks"  or  "silver  grain"  on  quarter-sawed  mate- 
rial. Wood  heavy  to  very  heavy.  Sapwood  rather 
narrow.  40-491.  THE  OAKS.  42. 

BB.  Rays  not  noticeable.  Color  grayish  brown,  texture 
coarse.  Sapwood  narrow.  Wood  moderately  light. 
30.  CHESTNUT.  1 

2.  Summerwood  figured  with  short  or  wavy  tangential  lines 

(running  more  or  less  parallel  with  the  rings),  often 
most  noticeable  toward  the  outer  part  of  the  growth 
ring.     (Compare  Plate  XVI,  figures  4  to  8.) 
AA.     Heartwood  not  distinctly  darker  than  sapwood  (sap- 
wood  sometimes  darker  than  heartwood  on  account 
of  sapstain.)     Rays  distinctly  visible  but  fine.    The 
wavy  tangential  lines  conspicuous  throughout  the 
summerwood.      Springwood    pores    numerous,    in 
more   than   one  row.     Color  pale   to  yellowish   or 
greenish    gray.      Wood    moderately    heavy.      37. 

HACKBERRY  or  SUGARBERRY.  4. 
BB.     Heartwood  distinctly  darker    than    sapwood.      Rays 

barely  visible. 
(1)     Springwood  pores  in  more  than  one  row. 

a.  Very  fine  broken  tangential  lines  visible  in  outer 
summerwood  and  especially  prominent  in  wide 
rings.  Sapwood  several  inches  wide,  heartwood 
brownish.  Most  pores  or  vessels  except  in  outer 
sapwood  appear  somewhat  closed,  difficult  to 

figure  indicates  an  average  weight  per  cubic  foot  of  the  wood  air  dry,  that 
is,  containing  12  to  15  per  cent  moisture.  U.  S.  Department  of  Agriculture  Bulletin 
556. 

^his  number  indicates  group  to  which  the  wood  belongs  in  the  box  wood  classi- 
fication. Pages  100,  104. 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS        119 

blow  through.  Wood  hard  and  heavy  except 
pumpkin  ash  which  usually  is  relatively  soft, 
weak  and  brash.  36-44. 

PUMPKIN  ASH.  '3. 
WHITE  ASH.  4. 
GREEN  ASH.  4. 

b.  Long  and  conspicuous  wavy  tangential  bands 
throughout  the  summerwood.  Sapwood  very 
narrow.  Heartwood  brown  with  reddish  tinge. 
Pores  rather  open.  Wood  moderately  heavy.  37. 

SLIPPERY  ELM.     3. 

(2)  Springwood  pores  in  one  more  or  less  continuous 
row  except  in  wide  rings  where  there  are  occasion- 
ally more.  Heartwood  brownish. 

a.  Pores  in   the   Springwood  fairly  conspicuous   and 

visible,  because  of  size  and  closeness  together. 
Pores  rather  open.  Wood  moderately  heavy. 
36.  WHITE  ELM.  3. 

b.  Pores    in    the    Springwood    inconspicuous,    hardly 

distinguishable  from  those  of  the  summerwood 
because  relatively  small,  often  not  close  to- 
gether, and  usually  filled  with  tyloses.  Wood 
heavy.  44. 

CORK  or  ROCK  ELM.     4. 

3.  Summerwood,  generally  not  figured  with  radial  or  tan- 
gential bands.  Rays  barely  visible.  Several  rows  of 
large  springwood  pores  which  are  usually  open  and  easy 
to  blow  through.  Sapwood  narrow,  rarely  over  three- 
fourths  of  an  inch  wide.  Heartwood  grayish  to  olive 
brown.  Wood  moderately  heavy.  34.  (Compare  Plate 
XVI,  figure  9.) 

BLACK  ASH.    3. 

B.  Diffuse-porous  woods — No  ring  of  large  pores  found  at 
the  beginning  of  each  year's  growth.  Pores  appear  as 
fine  grooves  on  the  longitudinal  cuts  and  are  scattered 
with  considerable  uniformity  throughout  both  the 
springwood  and  the  summerwood.  Pores  vary  in  size 
from  visible  to  the  naked  eye  to  barely  visible  or  indis- 
tinguishable without  a  lens.  The  relatively  small 
amount  of  difference  in  size  between  the  springwood 
and  summerwood  pores  makes  it  often  difficult  to  dis- 
tinguish the  annual  rings.  Some  of  these  woods  are 
rather  soft  and  light  but  are  separated  (because  they 


120  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

contain  pores  or  vessels)  from  "II,"  the  conifers,  or 
softwoods,  which  do  not  have  true  pores  or  vessels. 
Diffuse-porous  woods  are  found  in  groups  1,  3,  and  4  of 
-  the  box  woods.  Those  in  group  1  are  lightest.  (Com- 
pare Plate  XVI,  figures  10  to  12,  and  Plate  XVII,  fig- 
ures 1  to  11.) 

AA.  Individual  pores  plainly  visible.  Heartwood  light 
chestnut  brown.  Sapwpod  narrow.  Rays  not  vis- 
ible on  cross  section.  Wood  light  and  soft.  27. 
(Compare  Plate  XVI,  figure  10.) 

BUTTERNUT.     1. 

BB.     Individual  pores  barely  visible.    Sapwood  wide.    Rays 
not  visible  on  cross  section. 
(Compare  Plate  XV,  figures  11  and  12.) 

(1)  Pores    not    crowded.     Heartwood    reddish    brown. 

Wood  moderately  heavy  to  heavy.     38-44. 

BIRCH.     4. 

(2)  Pores  crowded.     Heartwood  grayish  to  brownish. 

Wood  moderately  light  to  light.     24-28. 

COTTONWOOD.     1. 
WILLOW.  1. 

CC.     Individual  pores  not  visible. 

(Compare  Plate  XVII,  figures  1  to  11.) 

(1)  Rays  comparatively  broad  and  conspicuous,  appear 

as  flecks  on  quartered  cuts  and  distinguish  these 
woods  from  conifers.  Color  various  shades  of 
light  reddish  brown. 

a.  Rays  crowded.     No  denser  and   darker  band  of 

summerwood  noticeable.     Wood  usually  lock- 
grained.     Moderately  heavy.     34. 

SYCAMORE.     3 

b.  Rays  not  crowded.    A  distinct  denser  and  darker 

band   of   summerwood   present.     Wrood   fairly 
straight-grained.     Heavy.     44. 

BEECH.     4. 

(2)  Rays  not  conspicuous  but  visible,  hence  distinguish- 

ing these  woods  from  conifers. 

a.  Heartwood  dingy  reddish  brown  often  with 
darker  streaks.  Sapwood  pinkish  white  mod- 
erately wide,  usually  over  an  inch ;  often  sold 
as  "sap  gum,"  sometimes  stained  blue  by  sap- 
stain.  Annual  rings  not  clearly  defined.  Rays 
very  fine,  close  together,  not  plain  even  on 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS        121 

quartered  cuts.    Wood  moderately  heavy.    34. 

RED  GUM.     3. 

b.  Heartwood  light  reddish  brown.     Sapwood  wide. 

Annual  rings  clearly  defined  by  a  thin  darker 
reddish  brown  layer.  Rays  fine  but  distinct, 
conspicuous  on  quartered  cuts  because  of 
darker  color. 

(a)  Wood  hard,  difficult  to  cut  across  the  grain. 

Pith  flecks  rare.     Rays  appear  to  be  not 
very  close  together    as    compared    with 
soft  maple.     Wood  heavy.     43. 
SUGAR  OR  HARD  MAPLE.     4. 

(b)  Wood  comparatively    easy    to    cut    across 

grain.     Pith  flecks  often  abundant.    Rays 
appear  very  close  together  as  compared 
with  hard  maple.     Wood  relatively  soft 
and  only  moderately  heavy.     32-37. 
SOFT  MAPLE.     3. 

c.  Heartwood  pale  to  yellowish    with    a    greenish, 

sometimes  (especially  in  yellow  poplar)  pur- 
plish tinge.  Sapwood  usually  over  1  inch  wide. 
Annual  rings  clearly  defined  by  a  fine  whitish 
line.  Wood  moderately  light  to  moderately 
heavy.  About  27-35. 

TULIP  or  YELLOW  POPLAR.  1. 

CUCUMBER  TREE.  1. 

MAGNOLIA.  1. 

d.  Heartwood   pale   or   creamy    brown    often    with 

scattered  dark  or  black  marks  or  streaks. 
Heartwood  not  sharply  defined  from  light 
creamy  colored  sapwood.  Wood  light.  26. 

BASSWOOD.     1. 

(3)     Rays  not  distinctly  visible  on  cross  section.     An- 
nual rings  usually  not  clearly  defined  which  aids 
in  distinguishing  these  woods  from  conifers, 
a.     Heartwood  distinctly  darker  than  sapwood. 

(a)  Heartwood,  reddish  brown.  Wood  fairly 
straight-grained,  pith  flecks  sometimes 
found.  Pores  visible  in  a  good  light, 
especially  on  longitudinal  surfaces  where 
they  appear  as  fine  lines  or  grooves. 
Wood  moderately  heavy  to  heavy.  38-44. 

BIRCH.     4. 


122  WOODEN   BOX   AND   CRATE   CONSTRUCTION 

(b)  "Heartwood  pale,  to  grayish  brown.  Wood 
often  very  cross  grained.  Moderately 
heavy.  34-35. 

BLACK  GUM.  3. 
TUPELO.      3. 

b.     Heartwood  not  distinctly  darker  than  sapwood. 
Wood  odorless,  tasteless. 

(a)  Color  creamy.    Annual  rings  inconspicuous, 

very  faintly  defined.  Tangential  surfaces 
show,  when  smoothly  cut,  faint  fine 
bands  running  across  the  grain  produced 
by  the  regularly  spaced  or  storied  rays 
"ripple  marks."  (See  Plate  XVII,  figure 
5.)  Wood  very  light  and  soft.  25. 
BUCKEYE.  1. 

(b)  Wood  whitish.     Annual   rings  clearly  de- 

fined by  a  fine  sometimes  whitish  line. 
No  figure  such  as  is  produced  by  storied 
rays.  Wood  light.  28. 

ASPEN  or  "POPPLE."     1. 

CONIFERS 

The  softwoods,  woods  obtained  from    scale    or    needle- 
leaved  trees.    Woods  without  pores. 

II.  No  pores  present — Wood  usually  appears  fine  textured 
because  the  cells  are  small  and  regularly  arranged  and 
because  no  cells  are  strikingly  larger  than  those  sur- 
rounding them.  Annual  rings  are  clearly  defined  by  a 
definite  band  of  summerwood.  Woods  light,  most  of 
them  in  box  wood  group  1.  A  few  heavier  conifers 
make  up  group  2  of  the  box  woods. 

A.     Odor  and  taste  spicy-resinous.     No  resin  ducts,  pitch 
pockets  or  accumulations  of  pitch  present. 

THE  CEDARS. 
(Compare  Plate  XVIII,  figures  1  and  2.) 

1.  Color  creamy  shading  to  a  pale  brown.    Heartwood 

odor  strong  in  green  material,  somewhat  suggests 
ginger.     Wood  moderately  light.    31. 

PORT  ORFORD  CEDAR.     1. 

2.  Heartwood  various  shades  of  red  and  brown ;  odor 

resembling  that  of  cedar  shingles.    Wood  light  to 
very  light.     22.  RED  CEDAR.        1. 

ARBORVITAE.     1. 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS        123 

B.  Odor  and  taste  not  spicy,  may  be  resinous,  especially 
in  the  pines.  Pitch  pockets  and  other  accumulations 
of  pitch,  including  small  exudations  on  the  ends  of 
boards,  often  present.  Knots  usually  more  or  less 
resinous.  Resin  ducts  present. 
1.  Heart  wood  darker  than  sapwood. 

AA.  Resin  ducts  visible  relatively  conspicuous  as 
small  light  specks  on  the  cross  section  or 
as  fine  lines  of  slightly  different  color  on 
the  longitudinal  surfaces.  Wood  with 
pitchy  resinous  odor  or  taste.  Heartwood 
creamy  to  orange  brown.  (Compare  Plate 
XVIII,  figures  7  to  9.) 

THE  PINES. 

(1)  Summerwood  relatively  inconspicuous,  not 

much  harder  or  denser  than  springwood. 
Change  from  springwood  to  summer- 
wood  gradual.  Heartwood  pale  creamy 
to  light  reddish  brown.  Resin  ducts 
often  conspicuous,  especially  in  sugar 
pine.  Wood  moderately  soft,  light.  26-29. 

WHITE  PINE.     1. 

SUGAR  PINE.      1. 

(2)  Summerwood   somewhat   denser  and  more 

conspicuous  than  in  (1).  Color  of  heart- 
wood  reddish  to  orange  "brown.  This 
group  midway  in  density  and  appearance 
between  (1)  and  (3).  Weight  28-34. 

WESTERN  YELLOW  PINE. 

LODGEPOLE  PINE. 

JACK  PINE. 

SCRUB  PINE. 

NORWAY  PINE. 

(3)  Summerwood    very   dense,  horny.     Change 

from  springwood  to  summerwood  often 
very  abrupt.  Resin  ducts  to  be  seen, 
especially  in  or  near  the  summerwood. 
Wood  heavy.  35-45. 

VIRGINIA  AND   CAROLINA   PINE.     2. 

SOUTHERN  YELLOW  PINE.  2. 

PITCH  PINE.  2. 


124  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

BB.  Woods  with  rather  inconspicuous  re-sin  ducts, 
without  piny  odor  but  with  somewhat 
resinous  odor  and  taste.  Marked  and  rather 
abrupt  change  from  spring-wood  to  sum- 
merwood.  Pitch  pockets  or  streaks  may  be 
found.  (Compare  Plate  XVIII,  figures  10 
to  12.) 

(1)  Color  of  heartwood  usually  reddish,  some- 

times with  yellow  cast.  Summerwood 
dense.  Scattered  resin  ducts  present. 
Often  several  seen  as  small  white  dots  in 
short  tangential  rows  in  or  near  the  sum- 
merwood.  Pitch  pockets  common.  Wood 
moderately  heavy.  30-34. 

DOUGLAS  FIR.  2. 

Sometimes    (DOUGLAS   SPRUCE, 
called        (OREGON  PINE. 

(2)  Heartwood    dull    russet    brown.     Summer- 

wood  sharply  defined  and  fairly  dense. 
Woods  moderately  heavy,  especially  that 
from  butt  cuts.  36. 

LARCH.  2. 

TAMARACK.     2. 

(3)  Heartwood  pale  reddish.     Transition  from 

springwood  to  summerwood  more  -grad- 
ual. Split  tangential  surfaces,  especially  if 
through  the  summerwood  of  narrow 
rings,  characteristically  indented  or  "dim- 
pled." (See  Plate  XIX.)  Split  surfaces 
show  "silky  sheen."  26. 

SITKA  SPRUCE.     1. 

2.  Heartwood  the  same  color  as  sapwood.  Woods  riot 
conspicuously  pitchy  though  resin  ducts  are  pres- 
ent and  pitch  pockets  may  occur.  Gradual  transi- 
tion from  springwood  to  summerwood.  (Split 
surfaces  show  "silky  sheen.")  Moderately  heavy. 
24-28. 

OTHER  SPRUCES.     1. 

C.     Wood  without  spicy  odor,  not  pitchy  or  resinous.     No 

resin  ducts,  pitch  pockets  or  accumulations  of  resin 

normally  present  in  the  wood  though  resin  may  in 

some  cases  exude  from  the  bark. 

1.     Heartwood   strongly  colored.     Summerwood  dense. 


STRUCTURE  AND  IDENTIFICATION   OF   WOODS         125 


126  WOODEN  BOX   AND    CRATE   CONSTRUCTION 

AA.  Heartwood  deep  brownish  red.  Wood  with- 
out markedly  characteristic  odor.  Annual 
rings  regular  in  width.  Wood  moderately 
light.  25-30. 

REDWOOD.     1. 

BB.  Heartwood  light  to  very  dark  brown.  Odor 
somewhat  rancid.  Longitudinal  surfaces 
feel  waxy.  Annual  rings  very  irregular  in 
width.  Weight  variable.  Average  30. 

CYPRESS.     1. 
2.     Heartwood  not  strongly  colored. 

AA.     Wood  whitish  at  least  in  springwood.     Sum- 
merwood  darker,  often  sharply  contrasted 
in  color,  tinged  with  red  or  purplish  brown. 
Wood  moderately  light  to  light.     23-28. 
THE  TRUE  FIRS.     1. 

BB.     Wood  has  slight  reddish  hue  in  both  spring- 
wood'  and  summerwood.      Wood  splintery, 
often  with  cup  shake.    Odor  somewhat  sour 
when  wood  is  fresh.     Moderately  light.   28. 
HEMLOCK.     2. 

DESCRIPTION    OF    BOX    WOODS 

The  letters  after  the  names  refer  to  the  various  regions 
in  which  the  trees,  grow  as  indicated  on  the  accompanying 
map,  figure  30,  although  the  geographical  distribution  of  each 
species  is  not  confined  exactly  to  the  limits  of  the  regions 
indicated.  For  scientific  names  see  U.  S.  Dept.  Ag.  Bui.  17, 
"Check  List  of  Forest  Trees." 

HARDWOODS 

RING- POROUS  WOODS 

The  Oaks— White  oak  group  (A,  B,  C,  D,  E). 
Red  oak  group  (A,  B,  C,  D,  E). 

These  species  grow  throughout  the  eastern  half  of  the 
United  States. 

They  are  heavy  and  hard  and  when  dry  are  without  char- 
acteristic odor  or  taste.  The  annual  rings  are  very  distinct 
in  both  the  white  and  the  red  oaks.  Under  a  lens  the  pores 
of  the  summerwood  of  the  white  oaks  are  very  minute  and  so 
numerous  that  they  are  difficult  to  count,  but  in  the  red  oaks 
the  opposite  is  true,  which  makes  these  species  easy  to  dis- 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS        127 

tinguish.  (Compare  figures  1  and  2,  Plate  XVI.)  The  most 
characteristic  feature  of  all  oak  woods  is  the  presence  of 
broad  medullary  rays  very  conspicuous  on  the  end  surface 
and  appearing  on  the  radial  surface  as  silvery  patches  from 
l/2  to  4  inches  in  height  with  the  grain.  This  structure  dis- 
tinguishes the  oaks  from  all  other  woods. 
Chestnut  (B,  D). 

The  region  of  growth  is  the  Appalachian  highland  and 
the  central  hardwood  section. 

The  wood  of  chestnut  is  moderately  light  and  usually 
straight-grained.     The  heartwood  is   grayish  brown,  with  a 
slightly  stringent  taste  due  to  the  tannin  in  it.     The  annual 
rings  are  made  very  distinct  by  a  broad  band  of  porous  spring- 
wood.    The  pores  in  the  summerwood  are  very  numerous  and 
arranged  in  irregular  radial  bands  similar  to  those  in  white 
oak.     (See  figure  3,  Plate  XVI.)     The  rays  are  much  finer, 
however,  than  in  the  oaks. 
The  Elms— White  elm  (A,  B,  C,  D,  E). 
Cork  elm  (B,  D). 

The  range  of  white  elm  is  the  eastern  half  of  the  United 
States,  that  of  cork  elm  being  confined  to  the  Appalachian 
highland  and  the  central  hardwood  section. 

The  wood  of  white  elm  is  moderately  heavy  and  easy  to 
work ;  that  of  cork  elm  is  heavier,  harder,  and  ranks  higher 
in  mechanical  properties. 

In  both  white  and  cork  elm  the  springwood  usually  con- 
sists of  but  one  row  of  large  pores,  those  of  the  latter  being 
smaller  and  filled  with  tyloses  in  the  heartwood.     (See  fig- 
ures 4  and  5,  Plate  XVI.) 
Hackberry— (B,  D,  E,  F,  parts  of  G  and  H). 

The  range  of  growth  includes  Montana,  Idaho,  and  the 
eastern  half  of  the  United  States,  except  the  northern  portion. 

The  wood  of  hackberry  is  moderately  heavy  and  generally 
straight-grained.  The  heartwood  is  light  gray,  tinged  with 
green,  which  helps  to  distinguish  this  species  from  the  elms 
in  which  the  heartwood  is  brownish,  usually  with  a  reddish 
tinge.  It  is  without  characteristic  odor  or  taste.  The  rays 
and  annual  rings  are  distinct  without  a  lens  which  also  helps 
to  distinguish  it  from  the  elms.  (See  figure  7,  Plate  XVI.) 
The  Ashes— White  ash  (A,  B,  C,  D,  E). 
Green  ash  (A,  B,  C,  D,  E). 

Black  ash  (A,  C,  and  northern  part  of  B  and  D). 
Pumpkin  ash  (Parts  of  E  and  western  D). 


128  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

The  range  of  white  and  green  ash  is  the  eastern  half  of 
the  United  States ;  of  black  ash,  the  northern  part  of  this  sec- 
tion, and  that  of  pumpkin  ash,  the  southern  portion.  White 
and  green  ash  are  very  much  alike  and  are  sold  as  "white  ash" 
or  "ash/'  The  lighter  weight  grades  of  white  and  green  ash 
are  commercially  classed  as  "pumpkin  ash." 

The  sapwood  of  each  is  comparatively  wide  and  white. 
The  heartwood  is  grayish  brown  occasionally  with  a  reddish 
tinge.  In  black  ash  the  sapwood  is  narrow,  usually  less  than 
one  inch  wide  and  the  heartwood  is  silvery  or  olive  brown, 
resembling  that  of  chestnut.  Black  ash  averages  consider- 
ably lighter  in  weight  than  the  other  two  species. 

All  species  have  definite  annual  rings  made  very  con- 
spicuous by  several  rows  of  large  pores  in  the  springwood. 
In  the  summerwood  the  pores  are  few,  very  small,  and  iso- 
lated, or  occasionally  two  or  three  in  a  radial  row.  Except  in 
black  ash,  these  pores  are  surrounded  by  light  colored  tissue 
which  projects  tangentially,  producing  light-colored  lines  often 
joining  pores  somewhat  separated,  especially  in  the  outer  por- 
tion of  the  annual  rings.  (See  figures  8  and  9,  Plate  XVI.) 
Elm  can  be  distinguished  from  ash  by  the  arrangement  of  its 
numerous  summerwood  pores  in  wavy  tangential  lines. 

DIFFUSE-POROUS    WOODS 

Butternut— (A,  B.  D). 

The  range  of  growth  is  the  northeastern  part  of  the 
United  States,  including  the  central  hardwood  section. 

Butternut  resembles  black  walnut  in  structure  but  is 
lighter  in  weight,  softer  and  lighter  colored,  resembling  black 
ash  or  chestnut  in  this  respect.  It  differs  from  the  woods 
previously  discussed  in  that  it  has  no  very  pronounced  group 
of  springwood  pores. 
Birch— (A,  B,  C,  D,  E). 

These  species  grow  chiefly  in  the  northern  portion  of  the 
United  States,  east  of  the  Mississippi  River. 

The  structure  of  the  different  birches  is  very  similar. 
The  wood  is  heavy,  fairly  straight-grained  and  without  char- 
acteristic odor  or  taste.  The  pores  are  barely  visible  to  the 
naked  eye  on  the  cross  section  but  quite  readily  visible  as 
grooves  on  the  longitudinal  surfaces.  The  annual  rings,  be- 
cause of  the  almost  uniform  size  of  .the  pores,  are  rather  in- 
distinct. Pith  flecks  are  very  often  present  in  birches. 

.The  birches  may  be  confused  with  the  maples.     In  the 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS        129 

maples,  however,  the  rays  on  the  cross  section  are  visible  to 
the  naked  eye,  while  in  the  birches  they  are  not.     Further- 
more, the  pores  of  the  maples  are  not  visible  to  the  naked  eye, 
while  those  of  the  birches  can  generally  be  seen  when  the 
wood  is  examined  in  a  good  light. 
Cottonwood— (B,  C,  D,  E,  F). 
Aspen— (A,  B,  C,  D,  F,  G,  H,  I). 

The  range  of  growth  of  cottonwood  is  all  of  the  eastern 
section  of  the  United  States  except  New  England  and  the 
northern  part  of  the  Rocky  Mountain  section ;  that  of  aspen 
is  all  sections  of  the  United  States  except  the  South  At- 
lantic and  Gulf  States. 

Both  species  are  light,  fairly  straight-grained,  and  with- 
out characteristic  odor  or  taste. 

There  is  practically  no  difference  in  color  between  the 
sapwood  and  heartwood  of  either  species.  The  pores  are 
larger  in  cottonwood  than  in  aspen.  The  rays  are  not  readily 
visible  to  the  naked  eye.  (See  figure  12,  Plate  XVI,  and  fig- 
ure 3,  Plate  XVII.) 

Cotton  gum  or  tupelo  resembles  cottonwood  but  usually 
is  heavier  and  has  smaller  pores.  Yellow  poplar  is  similar  in 
weight  and  hardness  but  its  greenish  tinge  usually  distin- 
guishes it.  Basswood  has  more  of  a  creamy  white  color, 
smaller  pores,  and  distinct  rays. 
Sycamore— (A,  B,  C,  D,  E). 

The  range  is  the  eastern  half  of  the  United  States. 

The  wood  is  moderately  heavy,  usually  lock-grained, 
without  characteristic  odor  or  taste.  The  heartwood  is  col- 
ored from  light  to  a  moderately  dark  reddish  brown,  some- 
times not  clearly  defined  from  the  sapwood.  The  pores  are 
very  small  and  crowded  together.  The  rays  are  very  charac- 
teristic; they  are  comparatively  broad  and  conspicuous,  al- 
though not  as  large  as  the  largest  rays  in  the  oaks.  They  are 
all  practically  of  the  same  size.  On  the  radial  surface  they 
appear  as  reddish  brown  "flakes,"  similar  to  the  rays  in  oak, 
but  smaller. 

Sycamore  is  not  easily  confused  with  other  woods.  Its 
conspicuous  rays  and  interlocked  grain  make  it  easily  recog- 
nizable. (See  figure  6,  Plate  XVII.)  It  resembles  beech 
somewhat,  but  can  be  distinguished  from  it  by  the  rays,  only 
a  small  portion  of  which  are  broad  in  beech.  Beech  also  is 
heavier  and  has  a  distinct  dense  band  of  summerwood. 


130  IVOODEN   BOX   AND    CRATE   CONSTRUCTION 

Beech— (A,  B,  D,  E, -eastern  half  of  C). 

This  species  grows  in  the  eastern  section  of  the  United 
States  and  also  in  northern  Wisconsin. 

Beech  is  a  hard  heavy  wood  without  characteristic  odor 
or  taste.  The  heartwood  has  a  reddish  tinge  varying-  from 
light  to  moderately  dark.  The  pores  are  invisible  without  a 
lens  and  decrease  in  size  slightly  and  gradually,  from  the  in- 
ner to  the  outer  portion  of  each  ring.  (See  figure  7,  Plate 
XVII.)  Some  of  the  rays  are  broad,  being  fully  twice  as  wide 
as  the  largest  pores  and  appearing  on  the  radial  surface  as 
reddish  brown  flakes.  The  other  rays  are  very  fine.  The 
maple  resembles  beech,  except  that  in  maple  the  widest  rays 
are  about  the  same  width  as  the  largest  pores  and  not  so  con- 
spicuous on  the  radial  surface. 
Red  gum — (D,  E,  and  part  of  B). 

Red  gum  grows  in  the  Appalachian  section  and  in  the 
Gulf  States. 

It  is  moderately  heavy,  somewhat  lock-grained,  and  with- 
out characteristic  odor  or  ta,ste.  The  sapwood  is  white  with 
a  pinkish  hue  or  pften  blued  with  sapstain.  The  heartwood 
is  reddish  browrn,  often  with  irregular  darker  streaks.  The 
wood  has  a  very  uniform  structure.  The  annual  rings  are  in- 
conspicuous and  pores  are  not  distinct  to  the  unaided  eye,  but 
the  rays  are  fairly  distinct  without  a  lens.  (See  figure  8,  Plate 
XVII.)  The  uniform  structure,  interlocked  grain,  and  red- 
dish browrn  color  are  usually  sufficient  to  distinguish  red  gum 
from  other  woods. 
The  Maples— Sugar  maple  (A,  B,  C,  D,  E). 

The  range  of  growth  of  this  species  is  the  eastern  half  of 
the  United  States. 

Sugar  maple  is  heavy,  hard  and  difficult  to  cut  across  the 
grain,  in  which  respect  it  differs  from  the  softer  maples.  The 
sapwood  is  white  in  all  maples,  and  the  heartwood  is  light 
reddish  brown,  without  characteristic  odor  or  taste.  The  an- 
nual rings  are  defined  by  a  thin  reddish  layer  usually  more 
conspicuous  on  dressed  longitudinal  surfaces.  The  pores  are 
all  very  small  and  uniformly  distributed  throughout  the  an- 
nual ring.  The  rays  are  distinct  without  a  lens  and  on  radial 
surfaces  they  are  conspicuous  as  small  reddish  brown  flakes. 
In  sugar  maple  only  part  of  the  rays  are  as  wide  as  the  pores ; 
the  others  are  very  fine,  being  barely  visible  with  a  lens.  The 
differences  between  the  soft  and  hard  maples  are  similar  to 
those  distinguishing  sycamore  and  beech,  although  in  the 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS        131 

maples  the  rays  are  finer.     In  soft  maple  the  rays  are  crowded 

as  in  sycamore.     Birch  and  beech  resemble  maple  somewhat. 

Birch  has  larger  pores,  visible  as  fine  grooves  on  the  dressed 

surfaces  and  the  rays  on  the  end  surfaces  are  not  distinctly 

visible  without  a  lens.     In  beech  some  of  the  rays  are  very 

conspicuous. 

Yellow  poplar— (B,  D,  E). 

The  range  of  growth  is  the  Appalachian  highland,  the 
central  hardwood  section  and  Gulf  States. 

Yellow  poplar  is  moderately  light,  straight-grained,  and 
without  characteristic  odor  or  taste.  The  heartwood  is  light 
to  a  moderately  dark  yellowish  or  olive  brown  with  a  green- 
ish and  sometimes  purplish  tinge  or  streaks.  The  annual 
rings  are  outlined  by  light-colored  lines.  The  pores  are  evenly 
distributed  throughout  the  annual  ring,  and  are  too  small  to 
be  visible  to  the  unaided  eye.  The  rays  are  distinct  without 
a  lens.  (See  figure  1,  Plate  XVII.) 
Cucumber  tree— (B,  D,  E). 

The  cucumber  tree  grows  in  the  same  locality  as  yellow 
poplar  except  in  Florida  and  the  South  Atlantic  Coast. 

It  is  easily  confused  writh  yellow  poplar  and  is  usually 
sold  as  such,  although  it  averages  slightly  heavier  in 'Weight. 
It  is  much  inclined  to  stain. 
Basswood— (A,  B,  C,  D). 

This  species  grows  in  the  eastern  half  of  the  United 
States. 

It  is  a  light,  soft,  straight-grained  wood  with  a  creamy 
brown  color.  The  heartwood  is  not  clearly  defined  from  sap- 
wood.  Sometimes  black  or  brownish  spots  or  streaks  are 
present.  It  is  without  taste,  but  has  a  slight  characteristic 
odor  even  when  dry.  The  pores  are  invisible  without  a  lens. 
The  rays  are  fairly  distinct  on  the  end  surface.  (See  figure 
11,  Plate  XVII.) 

Cottonwood  resembles  basswood,  but  is  more  grayish  in 
color,  has  larger  pores,  and  very  fine  rays.  Buckeye  also  re- 
sembles basswood  in  color  and  texture,  except  that  the  rays 
are  much  finer  and  are  visible  on  the  cross  section  only  with 
a  good  lens.  They  form  characteristic  so-called  "ripple 
marks"  on  the  tangential  surfaces.  (See  figure  4,  Plate 
XVII.) 

The  Gums— Black  gum  (A,  B,  D,  E). 
Cotton  gum  (southern  D,  E). 

Black  gum  grows  in  the  eastern  half  of  the  United  States, 


132  WOODEN  BOX  AND    CRATE   CONSTRUCTION 

except  in  northern  Michigan,  Wisconsin,  and  Minnesota,  and 
cotton  gum  in  the  Southern  Atlantic  and  Gulf  States. 

These  woods  are  moderately  heavy  to  heavy,  very  lock- 
grained.  They  are  without  characteristic  odor  or  taste.  The 
annual  rings  are  indistinct.  The  rays  and  pores  are  not  dis- 
tinct to  the  naked  eye.  The  weight,  lock  grain,  and  lack  of 
well  defined  summerwood  distinguish  these  woods  from  the 
conifers.  Their  lack  of  distinctive  characters  assists  in  their 
identification.  Cotton  gum  is  often  lighter  and  softer  in  the 
butt  log  than  near  the  top.  Cottonwood  sometimes  resembles 
tupelo,  or  cotton  gum,  but  its  more  visible  pores  serve  to 
identify  it.  (See  figure  2,  Plate  XVII.) 
Yellow  buckeye— (D). 

The  range  of  growth  of  this  species  is  the  Appalachian 
highland,  the  Ohio  valley,  and  into  Texas. 

This  wood  is  light,  soft,  straight-grained,  and  without 
characteristic  odor  or  taste.  The  heartwood  is  not  clearly 
differentiated  from  the  sapwood.  The  general  color  of  the 
wood  is  creamy  white  or  yellowish.  The  annual  rings  are 
often  not  clearly  defined.  The  pores  and  rays  are  not  visible 
to  the  naked  eye,  although  characteristic  "ripple  marks,"  pro- 
duced by  groups  of  rays,  may  be  seen  on  tangential  surfaces. 
(See  figures  4  and  5,  Plate  XVII.)  Buckeye  resembles  bass- 
wood  but  the  rays  in  basswood,  though  fine,  can  be  distin- 
guished more  readily  than  those  in  buckeye.  Buckeye  also 
somewhat  resembles  aspen. 

CONIFERS  (NON-POROUS  WOODS) 

The  Cedars — Western  red  cedar  (H). 

In  the  United  States  this  species  grows  in  the  northwest- 
ern part,  chiefly  in  Washington  and  Oregon. 

The  western  red  cedar  is  light  and  straight-grained.  The 
heartwood  is  reddish-brown,  with  the  characteristic  odor  of 
cedar  shingles  and  a  somewhat  bitter  taste  when  chewed. 
The  wood  contains  no  resin  ducts,  although  it  contains  a 
small  quantity  of  aromatic  oils.  The  annual  rings  are  dis- 
tinct, moderate  in  width,  with  a  thin,  but  well  defined  band 
of  summerwood.  Pores  are  entirely  absent,  and  the  rays  are 
very  fine.  (See  figure  2,  Plate  XVIII.) 
Northern  white  cedar  (A.  B.  C).- 

The  range  of  growth  is  the  northern  part  of  the  United 
States  from  Maine  to  Minnesota. 

This   species   resembles  western  red  cedar  in  odor  and 


STRUCTURE  AND  IDENTIFICATION  OF   WOODS        133 

taste,  but  usually  it  is  without  the  reddish  hue,  has  very  nar- 
row annual  rings,  and  averages  lighter  in  weight. 
Port  Or  ford  cedar  (H). 

This  species  grows  in  southwestern  Oregon  and  north- 
western California. 

It  is  a  moderately  light,  straight-grained  wood  with  a 
pronounced  odor  and  taste ;  the  odor  is  sometimes  compared 
to  that  of  ginger.  The  wood  is  less  spongy  than  that  of 
some  of  the  other  cedars.  The  odor  and  light  color  make  the 
identification  of  this  wood  easy.  (See  figure  1,  Plate  XVIII.) 
The  White  Pines — Eastern  white  pine  (A,  B,  C  and  parts  of 
D). 

Western  white  pine  (F,  H,  I). 

The  region  of  growth  of  eastern  white  pine  in  the  United 
States  is  the  northern  part  from  Maine  to  Minnesota,  and 
that  of  western  white  pine,  the  northwestern  part. 

The  wood  of  both  these  species  is  moderately  light, 
straight-grained  and  practically  tasteless,  but  has  a  slight, 
yet  pleasant  and  distinct  resinous  odor.  The  heartwood  is 
creamy  to  light  reddish  or  yellowish  brown.  The  annual 
rings  are  distinct,  but  the  summerwood  is  not  a  pronouncedly 
darker  or  appreciably  harder  layer.  The  outer  portion  of 
western  yellow  pine  logs  often  has  narrow  annual  rings  with 
a  very  thin  layer  of  summerwood  so  that  this  species  may 
approximate  the  white  pines  in  appearance,  and  consequently 
is  often  sold  as  white  pine.  It  may  be  distinguished,  how- 
ever, by  its  horny  glistening  layers  of  summerwood,  which 
are  especially  prominent  in  the  wider  rings. 
Sugar  pine  (I). 

Sugar  pine  grows  in  the  northern  part  of  California  and 
in  Oregon. 

It  is  very  much  like  the  white  pines  in  structure  and 
properties,  and  in  fact  belongs  to  the  white  pine  group  bo- 
tanically.  The  heartwood  is  very  light  brown,  only  slightly 
darker  than  the  sapwood  and  practically  never  reddish,  as  is 
the  case,  quite  often,  in  the  white  pines.  The  summerwood 
never  appears  as  a  horny,  glistening  band  as  in  the  hard 
pines.  The  wood  of  sugar  pine  has  a  slightly  coarser  texture 
than  that  of  white  pine ;  that  is,  the  fibers  and  also  the  resin 
ducts  have  a  greater  average  diameter.  Resinous  exudations, 
which  become  granular  and  have  a  sweetish  taste,  are  quite 
common  in  rough  sugar  pine  lumber,  and  when  present  are 
the  more  reliable  means  of  distinguishing  it  from  the  other 
pines.,  (See  figure  7,  Plate  XVIII.) 


134  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

The  Yellow  or  Hard  Pine  Group — Western  yellow  pine  (F,  G, 
H,  I). 

Norway  pine  (A,  C,  northern  half  of  B). 

Southern  yellozv  pine  (E). 

These  species  range  as  follows :  western  yellow  pine,  in 
the  Rocky  Mountain  and  Pacific  slopes ;  the  southern  yellow 
pine,  in  the  South  Atlantic  and  Gulf  States,  and  Norway  pine 
in  the  Northeastern  and  Central  States. 

The  yellow  pines  are  mostly  heavier,  harder,  more  resin- 
ous, and  contain  a  wider  and  harder  layer  of  summerwood 
than  the  white  pines.  However,  exceptions  occur,  notably 
western  yellow  pine,  which  in  the  outer  part  of  the  mature 
trees  is  often  as  light  in  weight  as  the  average  Avhite  pine. 
In  the  different  species  and  even  in  the  same  species  the  sap- 
wood  is  variable  in  width,  averaging  narrowest  in  some  spe- 
cies of  southern  yellow  pine.  The  heartwood  is  orange- 
brown  to  reddish-brown  color.  The  summerwood  is  usually 
defined  as  a  conspicuously  denser,  harder,  and  darker  band, 
but  in  very  narrow  rings  such  as  are  found  in  the  sapwood  of 
old  trees  of  western  yellow  pine  the  summerwood  layer  may 
be  very  narrow  and  inconspicuous.  The  resin  ducts  are  vis- 
ible with  a  lens  on  a  smoothly-cut  end  surface,  and  may  be 
seen  as  brownish  or  whitish  lines  on  the  longitudinal  surfaces. 
Douglas  fir  is  somewhat  similar  to  yellow  pine  in  appear- 
ance, but  usually  has  a  distinct  reddish  hue  and  less  prominent 
resin  ducts. 
Douglas  fir— (F,  G,  H,  I). 

Douglas  fir  grows  abundantly  in  the  Pacific  Northwest 
and  throughout  the  Rocky  Mountain  region. 

It  differs  from  the  true  firs  in  being  more  resinous, 
heavier,  stronger  and  in  having  a  distinctly  darker  heartwood. 
The  annual  rings  are  made  distinct  by  a  conspicuous  band 
of  summerwood.  Resin  ducts  are  present,  but  not  so  distinct 
as  in  the  pines,  usually  appearing  on  a  cross  section  as  whitish 
specks  in  the  summerwood.  (See  figure  10,  Plate  XVIII.) 
The  Spruces— White  spruce  (A,  B,  C). 

Red  spruce  (A,  B). 

Sitka  spruce  (H). 

Engelmann  spruce  (G,  F). 

White  spruce  grows  in  the  northern  part  of  the  United 
States  east  of  the  Mississippi,  red  spruce  in  the  same  section, 
except  in  the  western  part,  Sitka  spruce  in  western  Wash- 
ington and  Oregon,  and  Engelmann  spruce  in  the  Rocky 
Mountain  highland. 


STRUCTURE  AND  IDENTIFICATION  OF  WOODS          135 

These  species  are  moderately  light,  straight-grained 
woods.  In  the  white,  red,  and  Engelmann  spruce,  the  heart^ 
wood  is  as  light  colored  as  the  sapwood,  but  in  Sitka  spruce 
the  heartwood  has  a  light  reddish  tinge,  making  it  a  little 
darker  than  the  sapwood.  The  annual  rings  are  clearly  de- 
nned by  a  distinct  but  not  horny  band  of  summerwood. 
Spruce  resembles  the  white  pines  in  texture  but  has  a  silky 
sheen.  (See  Plate  XIX.)  On  account  of  its  reddish 
tinge  Sitka  spruce  might  be  confused  with  light  grades 
of  Douglas  fir  from  which  it  can  be  distinguished,  however, 
by  the  pocked  or  dimpled  appearance  of  split  tangential  sur- 
faces. (See  Plate  XIX.)  Douglas  fir  has  denser  summer- 
wood  except  in  very  narrow  rings;  therefore,  rings  of  aver- 
age width  should  be  compared.  Engelmann  spruce  is  some- 
what lighter  in  weight  and  weaker  than  the  other  spruces. 
Bald  cypress  (E). 

This  species  grows  abundantly  in  the  South  Atlantic 
and  Gulf  States. 

It  is  highly  variable  in  color  and  weight.  Commercially, 
the  common  cypress  is  classed  as  "white,"  "yellow,"  "red,"  or 
"black"  cypress,  although  it  is  all  derived  from  the  same 
botanical  species.  The  wood  has  a  characteristic  rancid  odor 
when  fresh.  In  dry  wood  the  odor  is  less  pronounced,  but 
can  be  detected  by  sawing  it  and  holding  the  sawdust  to  the 
nostrils.  The  wood  is  without  characteristic  taste.  The  an- 
nual rings  usually  are  irregular  in  width  and  outline.  The 
summerwood  is  very  distinct  but  narrow,  although  wider  than 
in  the  cedars.  (See  figure  3,  Plate  XVIII.)  Cypress  resem- 
bles the  cedars  and  redwood  somewhat;  but  the  cedars  have 
an  aromatic  odor  and  spicy  taste,  and  redwood  is  tasteless 
and  odorless. 
Redwood  (I,  along  the  coast). 

Redwood  grows  in  the  coast  region  of  northern  Cali- 
fornia. 

It  is  moderately  light,  straight-grained  and  obtainable  in 
large  clear  pieces.  The  heartwood,  as  a  rule,  is  deep  reddish 
brown  in  color.  Occasionally,  lighter  colored  pieces,  resem- 
bling western  cedar,  are  found.  The  wood  contains  no  resin 
ducts.  The  annual  rings  are  made  very  distinct  by  dense 
bands  of  summerwood  alternating  with  soft,  spongy  spring- 
wood.  (See  figure  6,  Plate  XVIII.)  Redwood  is  without 
characteristic  odor  or  taste. 


136  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

The  True  Firs— Balsam  fir  (A,  B,  C). 

Noble  fir  (H). 

White  fir  (G,  I). 

Red  fir  (I). 

Alpine  fir  (F,  G,  H). 

With  the  exception  of  balsam  fir  these  species  grow 
abundantly  in  the  Rocky  Mountain  highland  and  on  the 
Pacific  slopes. 

They  are  all  moderately  light,  straight-grained  and  with 
the  exception  of  Alpine  fir,  practically  without  characteristic 
odor  or  taste.  Alpine  fir  has,  when  dry,  a  distinctly  disagree- 
able odor.  The  color  of  the  wood  is  whitish,  often  with  a  red- 
dish brown  tinge,  which  is  especially  noticeable  in  the  sum- 
mer wood  bands.  This  produces  a  sharp  color  contrast  in  each 
ring  which  is  a  very  distinctive  character  in  most  of  the 
woods  of  this  group.  The  wood  is  very  uniform.  Rarely 
short  lines  of  resin  ducts  resulting  from  injury  may  be  found. 
The  firs  resemble  hemlock  but  the  weight  and  difference  in 
color  between  springwood  and  summerwood  are  often  suffi- 
cient to  distinguish  them. 
Hemlock— Hemlock  (A,  B,  C,  D). 

Western  hemlock  (F,  H). 

Hemlock  grows  in  the  eastern  half  of  the  United  States, 
except  in  the  southeast  portion.  The  range  of  growth  of 
western  hemlock  is  the  northwestern  part  of  the  United  States. 
These  woods  are  about  medium  in  weight  but  are  grouped 
with  the  heavier  conifers  for  box  and  crate  construction. 
They  are  usually  straight-grained,  sometimes  twisted,  and  the 
eastern  species  is  often  splintery  and  subject  to  cup  shakes. 
When  fresh,  hemlock  has  a  characteristic  sour  odor,  but  this 
practically  disappears  when  the  wood  is  dry.  There  is  little 
difference  in  color  between  sapwood  and  heartwood,  although 
the  latter  may  have  a  somewhat  pale  brown  or  reddish  hue. 
There  is  no  striking  contrast  in  color  between  the  spring- 
wood  and  summerwood  such  as  is  generally  found  in  the  firs, 
the  change  of  color  in  the  hemlocks  is  gradual.  The  rays  in 
hemlock  are  not  visible  to  the  naked  eye  and  the  wood  does 
not  normally  have  resin  ducts.  The  western  hemlock  is  less 
splintery  and  subject  to  cup  shakes  than  the  eastern  species. 
Tangential  lines  of  abnormal  resin  ducts  caused  by  injuries 
are  present,  especially  in  the  western  species. 


STRUCTURE  AND  IDENTIFICATION   OF   WOODS        137 
GRADING  RULES  FOR  ROTARY-CUT  BOX  LUMBER 

The  following  rules,  revised  May  20,  1919,  are  used  by 
the  Rotary  Cut  Box  Lumber  Association : 

Specifications  shall  always  be  furnished  by  buyer  to  man- 
ufacturer as  follows: 

Thickness   First 

Width   across   grain Second 

Length   with   grain Third 

1.  All  stock  shall  be  log  run,  the  full  cut  of  the  log,  and 
shall  be  free  from  rot  or  dote.     Pin-worm  holes,  sound  tight 
knots,  discoloration,  and  stain  are  no  defect. 

2.  All  stock  shall  be  machine-cut  to  thickness,  standard 
gears  as  furnished  by  lathe  manufacturers  to  be  used. 

3.  All  stock  shall  be  cut  tight,  and,  when  shipped,  shall 
weigh  not  to  exceed  3,100  pounds  per  thousand  board  feet  if 
kiln-dried,   or  3,400  pounds   per  thousand  board   feet  if  air- 
dried,  railroad  weights  at  point  of  shipment  to  govern.    Stock 
shall  be  sufficiently  flat  to  straighten  under  machine  without 
splitting. 

4.  A  trimming  allowance  of  y2  inch  in  length  shall  be 
made  on  all  stock  up  to  30  inches  long  and  of  1  inch  on  stock 
longer  than  30  inches,  all  lengths  to  have  J^-inch  trimming 
allowance  in  width ;  but  if  not  to  exceed  25  per  cent  in  any 
one  car  shall  measure  scant  of  the  J^-inch  trimming  allow- 
ance in  widths,  but  full  J4  inch,  it  shall  be  considered  up  to 
specifications. 

5.  All  cut-downs  in  width  that  accumulate  in  cutting  out 
defects  and  rounding  logs  shall  be  accepted  by  buyer,  these 
cut-downs  to  run  in  2-inch  multiples  down  to  4  inches,  unless 
otherwise  agreed ;  but  not  over  25  per  cent  of  contents  of  any 
car,  feetage  basis,  shall  consist  of  these  cut-downs.     When 
sawed  after  drying,  these  cut-downs  may  be  exact  width ;  but 
if  they  are  sized  green,  a  ^-inch  trimming  allowance,  when 
dry,  shall  be  made. 

6.  Checks  or  splits  not  longer  than  one-fourth  the  length 
of  the  piece,  but  in  not  more  than  15  per  cent  of  the  pieces  in 
each  shipment,  are  allowed,  provided  these  checks  or  splits 
are  reasonably  straight,  or  do  not  diverge  more  than  2  inches 
per  foot,  and  do  not  run  over  ]/'?.  inch  in  width  on  pieces  18 
inches   and   up   wide,    not   over   ^   inch   on   pieces    12   to    18 
inches  wide,  not  over  J^  mcn  on  pieces  6  to  12  inches  wide, 
and  not   over   %    inch   on   pieces  6  inches   and   under  wide. 


138  WOODEN   BOX   AND    CRATE    CONSTRUCTION 

Splits  or  checks  l/%  inch  and  under  wide  are  not  considered 
defects. 

7.  Specifications  on  all  sizes,  both  width  and  length, 
shall  not  be  divided  in  fractions  of  less  than  *4  inch. 

Other  Species — The  minor  kinds  of  boxwoods  are  graded 
as  follows:  The  hardwoods,  sycamore,  ash,  etc.,  may  be  or- 
dered as  No.  2  common,  according  to  the  rules  of  the  two 
hardwood  associations.  Larch  covers  eastern  tamarack 
(Northern  Pine  Manufacturers'  Association  rules)  and  west- 
ern larch  (Western  Pine  Manufacturers'  Association  rules). 
Noble  fir,  white  fir,  and  red  fir  are  admitted  in  No.  3  common 
under  the  West  Coast  Lumbermen's  Association  rules.  In 
California,  white  fir  and  red  fir  are  sold  with  the  box  grades 
of  California  pine.  Cedar  includes  southern  red  (no  standard 
rules),  northern  white  (no  standard  rules),  southern  white 
(no  commercial  rules  but  see  Navy  specification  3903b),  and 
western  red  cedar  (West  Coast  Lumbermen's  Association  and 
Pacific  Lumber  Inspection  Bureau).  Redwood  may  be  or- 
dered as  merchantable  in  accordance  with  the  rules  of  the 
California  Redwood  Association. 


APPENDIX 


TABLE  15.    CEMENT-COATED  COOLERS  OR  STANDARD  NAILS  AND  SINKERS  OR 
COUNTERSUNK  NAILS 


Net 

Dimension  of   Heads 

weight 

Size 

Number 

Length 

Gauge 
of 

Coolers2 

Sinkers2 

pounds 

per  keg 

inches 

wire 

Diam- 

Thick- ' 

Diam- 

Thick- 

eter 

ness 

eter 

ness 

Pounds 

inches 

inches 

inches 

inches 

2d 

85,700 

1 

16 

11/64 

.016 

5/32 

794 

3d 

54,300 

\y% 

15J/2 

3/16 

.013 

3/16 

•^  $ 

644 

4d 

29,800 

1% 

14 

7/32 

.029 

13/64 

3   C 

614 

5d 

25,500 

is/^ 

15/64 

.023 

7/32 

oJ  y 

704 

6d 

17,900 

l/^ 

13 

1/4 

.027 

7/32 

cS 

654 

7d 

15,300 

21/8 

12^2 

1/4 

.025 

15/64 

§    0> 

724 

8d 

10,100 

2/^ 

11^2 

19/64 

.025 

17/64 

•  *H 

71 

9d 

8,900 

2^ 

113/2 

9/32 

.029 

17/64 

>>  M 

68 

lOd 

6,600 

2//s 

11 

5/16 

.033 

9/32 

S  "^ 

63 

12d 

6,200 

3/^8 

10 

11/32 

.030 

21/64 

.S°— 

80 

16d 

4,900 

3M 

9 

21/64 

'cn.'S 

20d 

3,100 

3% 

7 

10 

iO 

11/32 

^  § 

83 

30d 

2,400 

6 

OJ 

o> 

13/32 

§| 

84 

40d 

1,800 

4^and 

5 

o 
c 

o 

c 

•M 

15/32 

-^.5 

82  to  85 

50d 

1,300 

5M 

4 

1 

8 

1/2 

J-u 

79 

60d 

1,100 

5^and 

3 

<u 

V 

8 

9/16 

c  ^ 

82 

5% 

& 

(/) 

c/5-c 

^Coolers  and  sinkers  are  identical  in  dimensions  and  count,  differing  only 
in  the  heads. 

2The  cooler  head  is  flat  and  of  good  size,  preferred  by  many  for  machine- 
driving  and  in  work  where  large  diameter  is  desired.  It  is  perfectly  satisfactory 
for  hand-driving  in  soft  wood. 

3The  sinker  head  is  reinforced  by  a  slight  countersinking,  which  reduces  the 
diameter.  It  will  not  break  or  pull  off,  and  is  recommended  for  hand-driving  in 
hardwood.  It  can  be  used  in  automatic  nailing  machines. 

4Weights    of    some    manufactures    are    one-half    pound    more. 

5The  sinker  type  of  head  is  used  on  coolers  larger  than  12d ;  the  larger  sizes 
are,  therefore,  identical  in  every  particular. 

Either  of  these  types  may  be  used  for  box  and  crate  work  if  regular  cement- 
coated  box  nails  are  not  available. 


139 


140  WOODEN   BOX   AND    CRATE   CONSTRUCTION 

TABLE  16.    CEMENT-COATED  Box  NAILS1 


Number 

Length 

Gauge 

Diameter 
at 

Thickness 
of 

Net  Weight 
per 

Size 

of  nails 

inches 

of 

head 

head 

keg 

K. 

wire 

per  iteg 

Inches 

Inches 

Pounds 

2d 

96,200 

7Ato  1 

16^ 

5/32 

.016 

67^  to  74 

3d 

64,600 

1/^6 

15}/6  or  16 

3/16 

.016 

68      to  80 

4d 

45,500 

i/^ 

15^2 

3/16 

.017 

64      to  72^ 

5d 

39,700 

i/^ 

15 

7/32 

.016 

74      to  78 

6d 

23,600 

i% 

13^  to  14 

1/4 

.022 

67^  to  77 

7d 

19,300 

2% 

13      to  13^ 

1/4 

.022 

69      to  72 

8d 

14,000 

2K  to  2% 

12H 

17/64 

.024 

70      to  75 

9d 

13,100 

2%  to  2^8 

12^ 

17/64 

.034 

71      to  78 

lOd 

8,900 

2J^ 

ll/^ 

9/32 

.037 

69^  to  75 

12d 

8,700 

3/^ 

11H 

9/32 

.031 

80      to  80^ 

16d 

7,100 

3/^ 

11 

5/16 

.030 

78 

20d 

5,200 

3/^j 

10 

11/32 

.036 

83 

30d 

4,600 

4% 

10 

3/8 

.030 

81 

40d 

3,500 

4^ 

9 

7/16 

.034 

84 

lrThe    variation    in    some    values    is    due    to    the    difference    in    the    manufacturing 
specifications   of  the  several  manufacturers. 


TABLE  17.    MISCELLANEOUS  CEMENT-COATED  NAILS 


Size  of 

head 

Net 

Type  of  nail 

Size 

of  nails 
per  keg 

Length 
inches 

of 
wire 

Diam- 
eter 
inches 

Thick- 
ness 
inches 

[per  keg 
pounds 

Egg  Case 

2d 

73  500 

1 

16 

3/16 

.013 

70 

,.        « 

3d 

51  700 

\y« 

15 

1/4 

.020 

70 

u            u 

Orange  Box.  .  .  . 
Fruit  Box 

4d 
4d 
4d 

30,500 
55,000 
45500 

llA 
IK 
1% 

14 
15 
15 

9/32 
13/64 
13/64 

.024 
.020 
.011 

70 

81 
73 

Apple  Box  
Berry  Box  

u              u 

Veneer  Box1  .  .  . 
Veneer2  

5d 

H" 
W 

4d 
4d 

31,000 
140,000 
125,000 
30,500 
19,700 

l*A 

ZA 
% 
ilA 
l% 

14 
17 
17 
14 
12 

7/32 
5/32 
5/32 
9/32 
5/16 

.019 
.011 
.013 
.018 
.020 

74 
70 
70 
70 

70 

u 

u 

5d 
6d 

13,000 
9,000 

i*A 

IK 

11 
10 

3/8 

1/2 

.021 
.029 

70 
70 

Barrel  

X' 

y*" 

iy* 
w 
w 

11A 

95,000 
67,200 
55,000 
48,000 
37,000 
26,000 
24,500 

K 

% 

1H 
IK 
1H 

VA 

15H 

14^ 
14H 
14^ 
14 
13 
13 

70 
70 
70 
70 
70 
70 
70 

»For  hoopless  orange  boxes. 

*For  use  in  3-ply  veneer  packing  cases. 


APPENDIX 


141 


NAMES    AND     DESCRIPTION     OF    GRADES     OF 
SUITABLE  FOR  PACKING  BOXES 

White  pine1 


LUMBER 


ITEM 

White  Pine  Associa- 
tion  of  the  Tona- 
wandas,    North    Tona- 
wanda,  N.  Y. 

Northern    Pine 
Manufacturers      Asso- 
ciation, Minneapolis, 
Minn. 

Western  Pine   Man- 
ufacturers Associa- 
tion,   Spokane,    Wash. 

Western    (Idaho) 

white  pine. 

Box  grade 

No.  1  box 

No.  4  common 

No.  4  common 

This  grade  admits 

1.  The  predominat- 

1. The  predominat- 

coarse   knots,    re- 

ing defect  charac- 

ing defects  charac- 

gardless    of     size 

terizing  this  grade 

terizing  this  grade 

and    not    necessa- 

is red  rot. 

are    red    rot    and 

rily  sound,  also  a 

2.  Other  types  are 

knot  holes. 

reasonable  amount 

pieces-showing 

2.  Other  types  are 

of  shake  or  stain. 

numerous  large 

pieces  showing 

worm  holes,  or 

numerous    large 

several  knot  holes, 

worm  holes,  pieces 

or  pieces  that  are 

that  are  extremely 

extremely    coarse, 

coarse,    knotted, 

knotted,  waney, 

waney,  or  showing 

shaky,     or    badly 

excessive  heart 

split. 

shake,     extremely 

3.  Pieces  which  are 

pitchy,    or    badly 

extremely  cross 

checked  or  split. 

checked  are  ad- 

missible in  this 

grade. 

Higher  grade 

No.  3  barn 

No.  3  common 

No.  3  common 

*No  standard  rules  for  New  England  white  pine  box  lumber  are  in  effect  at  the 
present  time   (1921). 


142 


WOODEN   BOX   AND    CRATE   CONSTRUCTION 


White  pine — Continued 


ITEM 

White  Pine  Associa- 
tion     of      the      Tona- 
wandas,    North    Tona- 
wanda,  N.  Y. 

Northern  Pine 
Manufacturers       Asso- 
ciation,      Minneapolis, 
Minn. 

Western    Pine    Man- 
ufacturers         Associa- 
tion,   Spokane,    Wash. 

Lower  grade 

No.  2  box 

No.  5  common 

No.  5  common 

Short     box  —  in- 

cludes  lumber    12 

to  47  inches  long 

inclusive,  3  inches 

and  wider,  and 

No.  4  and  better. 

Thicknesses, 

inches: 

Rough 

1,  1M,  1M,  2,  2Y2, 

3,  4. 

S1S\ 

S2SJ 

%/Not  adopted  by 
V%\     Ass'n. 

[1,  1M,  11A,  2. 

]||,1H,1H,1«. 

(Same  as  SIS. 

(1,  IK,  1H.2. 

\\\*  1H,  W,  1%. 
[Same  as  SIS. 

Widths,  inches. 

4,  5,  6,  8,  10,  12,  13 

Mixed  widths,  4 

Sold  in  mixed 

and  wider,  4  to  16 

and  wider,  or  in 

widths,  4  and 

with  average  of  9 

specified  widths 

wider. 

or  better,  4  to  12 

of  4,  6,  8,  10,  12, 

S2E—  Yi  off. 

averaging  at  least 

13      and    wider. 

8  may  be  specified. 

Average  of  9  may 

be  specified  if 

ordered    4    to    16. 

Best  to  order  4  to 

12  averaging  at 

least  8. 

S2E—  Y2  off. 

Length,  feet. 

6,  8,  10,  12,  14  and 

6,  8,  10,  12,  14,  16, 

Sold    in    mixed 

16.     6  to  16  aver- 

18 or  20.      6  to  16 

lengths,  6  and 

aging  at  least   12 

averaging  at  least 

longer.       6  to  16 

may  be  specified. 

12  may  be  speci- 

averaging at  least 

fied. 

12  may  be  speci- 

fied. 

APPENDIX 


143 


Yellow  pine,  including  North  Carolina  pine 


ITEM 


Southern  Pine  Association,  New 
Means,  La. 

Georgia-Florida,  Sawmill  Asso- 
:iation,  Jacksonville,  Fla. 


North  Carolina  Pine  Association, 
Norfolk,  Va. 


Box  grade 


Southern  yellow  pine. 
No.  2  common 

Mo.  2  common  boards  dressed 
one  or  two  sides;  admits 
knots  not  necessarily  sound, 
but  the  mean  or  average  di- 
ameter of  any  one  knot  must 
not  be  more  than  one-third 
of  the  cross-section  if 
located  on  the  edge  and 
must  not  be  more  than  one- 
half  of  the  cross-section  if 
located  away  from  the  edge; 
a  sound  knot  may  extend 
over  one-half  the  cross- 
section  if  located  on  the  edge, 
except  that  no  knot  the  mean 
or  average  diameter  of  which 
exceeds  4  inches  is  admitted 
admits  also  worm  holes, 
splits  one-fourth  the  length 
of  the  piece,  wane  2  inches 
wide,  or  through  heart 
shakes  one-half  the  length 
of  the  piece,  through  rotten 
streaks  %  inch  wide  one- 
fourth  the  length  of  the 
piece,  or  its  equivalent  oi 
unsound  red  heart;  or  defects 
equivalent  to  the  above. 

A  knot  hole  3  inches  in  di- 
ameter will  be  admitted,  pro 
vided  the  piece  is  otherwise 
as  good  as  No.  1  common 
Miscut  1-inch  common 
boards  which  do  not  fal 
below  %  inch  in  thickness 
are  admitted  in  No.  2  com 
mon,  provided  the  grade  o 
such  thin  stock  is  otherwise 
as  good  as  No.  1  common. 


vlorth  Carolina  pine. 
Box 

.umber  below  the  grade  of 
No.  3,  containing  pinholes, 
pin,  standard,  and  large, 
reasonably  sound  knots, 
stain  not  exceeding  25  per 
cent,  and  pith  knots,  en- 
cased knots,  and  spike  knots 
which  do  not  seriously  affect 
strength  of  piece;  stained 
pieces  otherwise  No.  1  and 
2  grade,  which  show  over  50 
per  cent  stain,  and  stained 
pieces  otherwise  grading 
No.  3  and  showing  not  more 
than  33^  per  cent  stain;  and 
pitchy  pieces  which  are  not 
desirable  in  No.  1,  2  and  3 
grades.  Lumber  which 
would  otherwise  grade  No.  1, 
2  and  3  containing  50  per 
cent  firm  red  heart  will  be 
admitted  in  this  grade. 
Reverse  side  of  box  boards 
may  be  cull. 


144 


WOODEN   BOX   AND    CRATE   CONSTRUCTION 


Yellow  pine — Continued 


ITEM 


Higher  grade 
Lower  grade 


Thicknesses, 
inches: 
Rough 
SIS 

S2S 

Widths,  inches: 


Lengths,  feet: 


Southern  Pine  Association.jNew 
Orleans,  La. 

Georgia-Florida,  Sawmill  Asso- 
ciation, Jacksonville,  Fla. 

No.  1  common 
No.  3  common 


1,  1M,  IK- 
%,  1«,  1«- 
Same  as  SIS. 

3  and  up,  in  multiples  of  I, 
not  over  K  inch  scant  on  8 
and  under,  %  on  9  or  10  and 
%  on  ii  and  12  or  wider. 


S.  P.  A.  4  to  2-4  in  multiples 
of  2.  G.— F.  S.  A.  8  to  20 
in  multiples  of  1. 

An  average  of  15  may  be 
specified. 


North  Carolina  Pine  Association, 
Norfolk,  Va. 

No.  3 

Culls  and   merchantable  red 
heart. 


,  1M,  IK,  1%,  2. 


Stocks— 6,  8,  10  and  12,  Edge 
— random  widths  under  12 
except  6,  8,  10  inches,  which 
are  stocks.  4/4  edge  is  3 
and  wider,  5/4  to  8/4  edge 
is  4  and  wider.  %  in  width 
shall  be  allowed  for  dressing 
6  and  under  boards  four 
sides,  but  K  shall  be  allowed 
for,  dressing  boards  wider 
than  6. 

8  to  16  in  multiples  of  2,  not 
exceeding  5  per  cent  of  8 
foot. 

An    average    of    12    may    be 
specified. 


APPENDIX 


145 


Spruce 


ITEM 

West  Coast  Lumber- 
men's    Association, 
Seattle,  Wash. 
Pacific    Coast    Lum- 
aer  Inspection  Bureau, 
Inc. 

Spruce       Manufac- 
turers' Association  (Not 
active   although   grad- 
ng  rules  are  still  used). 

Sitka    spruce    box 

Appalachian  spruce 

New    England 

lumber. 

box. 

spruce. 

Box  grade 

The   value   and 

Large  black  knots, 

No  standard  grad- 

grade of  this 

knots    not    sound 

ing    rules    are    in 

lumber    is    deter- 

in  character,  knot 

effect  .       The 

mi  ned    by    its 

holes,     heart 

lumber   is   graded 

adaptability  for 
the  manufacture  of 

checks  or  shakes, 
black    sap    and 

principally  accord- 
i  n  g     to    verbal 

ordinary     packing 

small    amount    of 

understanding  be- 

boxes, ordinary 

hard  red  wood  ad- 

tween  buyer   and 

sizes  being  defined 

mitted. 

seller  or  according 

as  boxes  not  over 

Wane  or  bark  equal 

to  local  specifica- 

20 inches  in  length 

to  half  the  thick- 

tions   which   have 

nor  more  than  15 

ness  and  one- 

been  in  use  for  a 

inches  in  width. 

fourth  the  length 

number   of   years. 

Wide  boards  or 

on  the  face  or 

those  of  special 

equal    to    20    per 

Massachusetts 

widths  will  admit 

cent   of  the   piece 

State  Law  for  the 

more  defects  than 

on   the   back,   ad- 

inspection    of 

narrow  or  random 

mitted. 

Lumber. 

widths. 

Season  checks  or 

Box  boards,  waney 

Grades  —  There  are 

splits  equal  to  % 

edged  box  boards, 

three  recognized 

the  length  of  the 

pine,    bass    wood, 

grades  of  box  lum- 

piece admitted. 

poplar  and  spruce 

ber,    viz.:    No.    1, 

Pin  worms  and 

are  inspected  as 

No.  2  and  No.  3. 

scattering  grub 

good  and  culls. 

No.  1  —  Generally 

holes   admitted. 

Good    includes    all 

sound,  and  con- 

This grade  is  de- 

sound   lumber    so 

tains  from  75  per 

signed    for    boxes 

free  from  black, 

cent  to  90  per  cent 

and  crating  and 

mouldy,  or  rotten 

of  cuttings  suit- 

some waste  or  bad 

sap,  rot,  worm 

able  for  boxes  ol 

material    is    al- 

holes   and   bad 

ordinary  size  and 

lowed. 

shakes,    that    not 

quality,  as  re- 

less than  ^  of  the 

ferred   to  above. 

entire  piece  (as  a 

In  computing  per- 

whole) can  be  used 

centages,  cuttings 

without     waste. 

of  assorted  sizes 

Culls  include  a\ 

are  used.     Assort- 

lumber not  good 

ed  sizes  are  defined 

enough  for  the 

as  pieces  running 

above  grade. 

in  widths  from  6 

The  Navy  Depart- 

inches to  12  inches, 

ment  has  the  fol- 

and  in    lengths 

lowing  rule  for 

from  12  inches  to 

New    England 

20  inches. 

spruce     (39Slb.): 

146 


WOODEN   BOX   AND    CRATE   CONSTRUCTION 


Spruce — Continued 


ITEM 


Higher  grade 
Lower  grade 

Thicknesses, 
inches: 
Rough 
SlSorS2S 

Widths,  inches: 
Rough 
S2E 

Length,  feet 


West  Coast  Lumber- 
men's Association, 
Seattle,  Wash. 

Pacific  Coast  Lum- 
)er  Inspection  Bureau, 
nc. 


Spruce  Manufac- 
urers'  Association(Not 
active  although  grad- 
ng  rules  are  still  used). 


Sitka  spruce  box 
lumber — Cont'd. 
Jo.  2 — Generally 
similar  in  charac- 
ter to  No.  1,  con- 
taining 60  per  cent 
to  75  per  cent  of 
box  cutting. 

No.  3— All  lumber 
below  the  grade  of 
No.  2  and  contain- 
ing 40  per  cent  to 

^60  per  cent  of  box 
cuttings. 


No.  1  common. 
None. 


i,  IK,  IK,  15*. 

4,6,8,  10,12. 

iik- 2 

6  to  20  in  multiples 
of  2. 


Merchantable. 
Mill  culls. 


4  and  wider. 

^,  5%,  7y8,  v 
ny2. 

6  arid  longer.  Not 
over  5  per  cent  6 
feet. 


STew  England 
spruce — Cont'd. 
Box:  (a)  Sizes: — 
Lengths  to  be  ran- 
dom 6  feet  and  up. 
Widths  to  be  4 
inches  and  up  as 
specified.  Thick- 
nesses as  specified, 
(b)  Defects  allow- 
ed — This  grade 
will  admit  the  fol- 
lowing: Large 
branch  and  black 
knots,  knot  holes, 
worm  holes, 
stained  sap,  and  a 
reasonable  amount 
of  hard  red  rot. 
Wane  not  exceed- 
ing one-half  the 
thickness  of  piece 
and  extending  full 
length  on  one  edge 
only  or  a  propor- 
tional amount  on 
two  edges.  Shakes, 
splits  or  checks 
equal  to  %  length 
of  piece. 


APPENDIX 


147 


Red  and  sap  gum 


ITEM 


National  Hardwood  Lumber  Association,  Chicago,  111. 

American  Hardwood  Manufacturers'  Association,  Memphis,  Tenn. 


Box  grades 


Higher  grade 
Lower  grade 
Thicknesses 
Widths,  inches 
Lengths,  feet 


No.  2  common  red  and  sap  gum. 

Pieces  3  to  7  inches  wide,  4  to  10  feet  long  must  work  50 
per  cent  clear  face  or  sound  sap  in  not  over  three  cuttings; 
pieces  3  to  7  inches  wide,  11  feet  and  longer  must  work  50 
per  cent  clear  red  face  or  sound  sap  in  not  over  four  cut- 
tings; pieces  8  inches  and  over  wide,  4  to  9  feet  long  must 
work  50  per  cent  clear  red  face  or  sound  sap  in  not  over 
three  cuttings;  pieces  8  inches  and  over  wide,  10  to  13 
feet  long  must  work  50  per  cent  clear  red  face  or  sound 
sap  in  not  over  four  cuttings;  pieces  8  inches  and  over 
wide,  14  feet  and  over  long  must  work  50  per  cent  clear 
red  face  of  sound  sap  in  not  over  five  cuttings.  No  cut- 
ting to  be  considered  which  is  less  than  3  inches  wide  by 
2  feet  long.  Sound  discolored  sap  is  no  defect  in  any 
grade  of  sap  gum. 

No.  1  common. 
No.  3  common. 
See  Table  9. 

3  and  over  in  random  widths,  average  of  9  may  be  specified. 

4  and  over,  but  not  more  than  10  per  cent  4  and  5  foot 
lengths  admitted  in  this  grade.     Average  of  11  may  be 
specified. 


148 


WOODEN  BOX   AND    CRATE   CONSTRUCTION 


Western  yellow  pine 


ITEM 


Western     Pine     Manufacturers 
Association,    Spokane,    Wash. 


California  White  and  Sugar  Pine 
Manufacturers'   Association. 


Box  grade 


Higher  grade 
Lower  grade 

Thicknesses, 
inches: 
Rough 
SIS  or  S2S 

Widths,  inches 
Length,  feet 


"W.estern  white  pine." 
No.  4  common. 

1'.     The   defects   common 
this  grade  are  much  the  same 
as  those  in  No.  3  but  greater. 

2.  The  most  common  serious 
defects  are  knot  holes,  and 
either  red  rot,  or  its  equiva- 
lent in  heavy  massed  pitch. 
Other  types  are:  extremely 
coarse    knotted,    or   waney, 
or  badly  split,  or  badly 
checked   pieces,    or   pieces 
with  excessive  heart  shake. 

3.  This  grade  especially 
meets   the   demands   of  the 
box  manufacturer  for  a  soft, 
easily-worked  pine  in  a  grade 
that  yields  well  in  cut-up  box 
product. 


No.  3  common. 
No.  5  common. 


if,  1H,  1H,  1%. 

4    and    wider.     If    S2E, 
scant. 


6  and  longer. 


"California  white  pine." 
No.  3  common  and  fencing. 

to  The  general  appearance  of 
this  grade  of  lumber  is  coarse. 
It  admits  large,  loose  or 
unsound  knots,  an  occasional 
knot  hole,  some  shake,  worm 
holes,  some  red  rot,  any 
amount  of  stained  sap,  but 
not  a  serious  combination  of 
these  defects  in  any  one 
piece. 

A  grade  similar  to  No.  3  com- 
mon is  sometimes  sold  as 
No.  1  Box  in  California. 

No.  4  common  and  strips. 

The  predominating  defects 
characterizing  this  grade  are 
red  rot,  pitch,  and  stain. 
Other  types  are  pieces  show- 
ing numerous  large  worm 
holes,  or  pieces  that  are  ex- 
tremely coarse  knotted, 
waney,  shaky,  or  badly  split. 

A  grade  similar  to  No.  4  com- 
mon is  sometimes  sold  as 
No.  2  box. 

No.  3  common. 
None. 


1,  IK,  IK,  2. 

K,  1A,  HI,  lif. 

4  and  wider. 
6  and  longer. 


APPENDIX 


149 


Cottonwood 


ITEM 


National  Hardwood  Lumber  Association 
American  Hardwood  Manufacturers'  Association 


Box  grade 


Higher  grade 
Lower  grade 
Thicknesses 

Widths,  inches 
Lengths,  feet 


No.  2  common. 

Pieces  3  to  7  inches  wide,  4  to  10  feet  long  must  work  50 
per  cent  sound  in  not  over  three  cuttings;  pieces  3  to  7 
inches  wide,  11  feet  and  longer  must  work  50  per  cent 
sound  in  not  over  four  cuttings;  pieces  8  inches  and  over 
wide,  4  to  9  feet  long  must  work  50  per  cent  sound  in  not 
over  three  cuttings;  pieces  8  inches  and  over  wide,  10  to 
13  feet  long  must  work  50  per  cent  sound  in  not  over  four 
cuttings;  pieces  8  inches  and  over  wide,  14  feet  and  over 
long  must  work  50  per  cent  sound  in  not  over  five  cuttings. 

No  cutting  to  be  considered  which  is  less  than  3  inches 
wide  by  2  feet  long. 

No.  1  common. 
No.  3  common. 
See  Table  9. 

3  and  over,  average  of  9  may  be  specified.  4  and  over,  not 
to  exceed  10  per  cent  of  4  and  5  foot  lengths.  Average  of 
11  may  be  specified. 


150 


WOODEN  BOX  AND  CRATE  CONSTRUCTION 


Yellow  poplar 


ITEM 


National  Hardwood  Lumber  Association 
American  Hardwood  Manufacturers'  Association 


Box  grades 


Higher  grade 
Lower  grade 
Thicknesses 
Width,  inches 
Lengths,  feet 


No.  2-B  common. 

No.  2  common  is  divided  into  No.  2-A  common  and  No.  2-B 
common,  but  unless  otherwise  specified  is  to  be  considered 
as  a  combined  grade. 

Sound  discolored  sap  is  no  defect  in  this  grade. 

No.  2-B  common — pieces  3  to  7  inches  wide,  4  to  10  feet 
long  must  work  50  per  cent  sound  in  not  over  three  cut- 
tings; pieces  3  to  7  inches  wide,  11  feet  and  longer  must 
work  50  per  cent  sound  in  not  over  four  cuttings;  pieces 
8  inches  and  over  wide,  4  to  9  feet  long  must  work  50  per 
cent  sound  in  not  over  three  cuttings;  pieces  8  inches  and 
over  wide,  10  to  13  feet  long  must  work  50  per  cent  sound 
in  not  over  four  cuttings;  pieces  8  inches  and  over  wide, 
14  feet  and  over  long  must  work  50  per  cent  sound  in  not 
over  five  cuttings. 

No  cutting  to  be  considered  which  is  less  than  3  inches  wide 
by  2  feet  long. 

No.  2-A  common  and  No.  1  common. 
No.  3  common. 
See  Table  9. 

3  and  over,  average  of  9  may  be  specified. 

4  and  over,  not  more  than  10  per  cent  of  4-  and  5-foot 
lengths.      Average  of  9  may  be  specified. 


APPENDIX 


151 


Hemlock 


ITEM 

West  Coast  Lumber- 
men's Association 

Northern  Hemlock 
and  Hardwood  Manu- 
acturers'  Association 

Eastern  States  Hem- 
lock 

Box  grade 

No.  2  common. 

Box    and    crating 

inch  and  dimen- 

sion. 

Must  be  free  from 

Stock  that  will  cut 

Spruce  Manufac- 

rot.   Admits  large, 

at  least  50  per 

turers'  Association 

coarse    knots    ap- 

cent of  firm,  useful 

rules  sometimes 

proximately     2 
inches  in  diameter 

box     and     crating 
stock.     Includes 

used  in  West  Vir- 
ginia and     North 

in    4-inch    and    6- 

No.  3  hemlock, 

Carolina.     In 

inch  stock,  2*/2 

4/4  and   8/4,   2 

Pennsylvania, 

inches  in  Sand  10- 

inches  and  wider, 

New  York,  and 

inch,  and   Y$  the 

4  feet  and  longer, 

New   England 

width  of  the  piece 

and  admits  defects 

local  rules  for 

in  12-inch  and 

of  the  following 

"Box"  followed. 

wider,  spike  knots, 

character: 

any  amount  of 

Soft  rot,  open  shake, 

, 

solid  heart  or  sap 

coarse  loose  knots 

stain,     a      limited 

and  knot  holes,  or 

number  of  well 

any    other    defect 

scattered  worm 

that  is  character- 

holes,   solid    pitch 

istic    of    hemlock, 

or   pitch    pockets, 

that  will  weaken 

small  amount  of 

stock  to  the  ex- 

fine shake,  wane  2 

tent  of  barring  its 

inches  wide,   if  it 

use  for  dimension 

does  not  extend 

purposes. 

into   the   opposite 

This  grade  must  be 

face.     A  serious 

based  on  the  per- 

combination  of 

centage   of   useful 

above    defects    in 

material  that  each 

any   one    piece   is 

piece  contains,  as 

not  permitted.     A 

it  is  impossible  to 

board  may  have 

describe  the  de- 

one large  knot 

fects    which     this 

hole,  provided  the 

stock  contains. 

piece  is  otherwise 

as  good  as  No.   1 

common. 

152 


WOODEN   BOX   AND    CRATE   CONSTRUCTION 


Hemlock — Continued 


ITEM 

West  Coast  Lumber- 
men's Association 

Northern      Hemlock 
and   Hardwood   Manu- 
facturers' Association 

Eastern  States  Hem- 
lock 

Higher  grade 

No.  1  common. 

Select   No.  3   com- 
mon. 

Lower  grade 

No.  3  common. 

No.  4  common. 

Thicknesses, 
inches: 
Rough 
SIS 
S2S 

1,  1M,  1^,  2. 
Same  as  SIS. 

%)  1J^- 

If!  i^l' 

Widths,  inches 
S1E 

4,  6,  8,  10,  12. 

3^,  5^,  7M,  9M. 

2,  4,  6,  8,  10,  12. 
34,  to  ^g  scant. 

S2E 

Same  as  S1E. 

^  scant. 

Lengths,  feet. 

10  to  20. 

4  to  20  in  multiples 
of  2. 

APPENDIX 


153 


Soft  maple  and  soft  elm 


ITEM 


National  Hardwood  Lumber  Association 
American  Hardwood  Manufacturers'  Association 


Box  grade 


Higher  grade 
Lower  grade 
Thicknesses 
Widths,  inches 
Lengths,  feet 


No.  2  common. 

Pieces  3  to  7  inches  wide,  4  to  10  feet  long  must  work  50 
per  cent  sound  in  not  over  three  cuttings;  pieces  3  to  7 
inches  wide,  11  feet  and  over  long  must  work  50  per  cent 
sound  in  not  over  four  cuttings;  pieces  8  inches  and  over 
wide,  4  to  9  feet  long  must  work  50  per  cent  sound  in  not 
over  three  cuttings;  pieces  8  inches  and  over  wide,  10  to  13 
feet  long  must  work  50  per  cent  sound  in  not  over  four 
cuttings;  pieces  8  inches  and  over  wide,  14  feet  and  over 
long  must  work  50  per  cent  sound  in  not  over  five  cuttings. 

No  cutting  to  be  considered  which  is  less  than  3  inches 
wide  by  2  feet  long. 

No.  1  common. 
No.  3  common. 
See  Table  9. 

3  and  over,  average  of  7  may  be  specified. 

4  and  over,  not  over  10  per  cent  4-  and  5-foot  lengths. 
Average  of  11  may  be  specified. 


154 


WOODEN   BOX   AND    CRATE   CONSTRUCTION 


Birch 


ITEM 


National  Hardwood  Lumber  Association 
American  Hardwood  Manufacturers'  Association 


Box  grades 


Higher  grade 
Lower  grade 
Thicknesses 
Widths,  inches 
Lengths,  feet 


No.  2  common. 

Pieces  3  to  7  inches  wide,  4  to  10  feet  long  must  work  50 
per  cent  clear  face  in  not  over  three  cuttings;  pieces  3  to  7 
inches  wide,  11  feet  and  over  long  must  work  50  per  cent 
clear  face  in  not  over  four  cuttings;  pieces  8  inches  and 
over  wide,  4  to  9  feet  long  must  work  50  per  cent  clear 
face  in  not  over  three  cuttings;  pieces  8  inches  and  over 
wide,  10  to  13  feet  long  must  work  50  per  cent  clear  face 
in  not  over  four  cuttings;  pieces  8  inches  and  over  wide, 
14  feet  and  over  long  must  work  50  per  cent  clear  face  in 
not  over  five  cuttings. 

No  cutting  to  be  considered  which  is  less  than  3  inches 
wide  by  2  feet  long. 

No.  1  common. 
No.  3  common. 
See  Table  9. 

3  and  over,  average  of  7  may  be  specified. 

4  and  over,  not  over  10  per  cent  4-  and  5-foot  lengths. 
Average  of  11  may  be  specified. 


APPENDIX 


155 


Basswood 


ITEM 


National  Hardwood  Lumber  Association 
American  Hardwood  Manufacturers'  Association 


Box  grades 


Higher  grade 
Lower  grade 
Thicknesses 
Widths,  inches 
Lengths,  feet 


No.  2  common. 

Pieces  3  to  7  inches  wide,  4  to  10  feet  long  must  work  50 
per  cent  sound  in  not  over  three  cuttings;  pieces  3  to  7 
inches  wide,  11  feet  and  over  long  must  work  50  per  cent 
sound  in  not  over  four  cuttings;  pieces  6  inches  and  over 
wide,  4  to  9  feet  long  must  work  50  per  cent  sound  in  not 
over  three  cuttings;  pieces  8  inches  and  over  wide,  10  to  13 
feet  long  must  work  50  per  cent  sound  in  not  over  four 
cuttings;  pieces  8  inches  and  over  wide,  14  feet  and  over 
long  must  work  50  per  cent  sound  in  not  over  five  cuttings. 

No  cutting  to  be  considered  which  is  less  than  3  inches 
wide  by  2  feet  long. 

No.  1  common. 
No.  3  common. 
See  Table  9. 

3  and  over.     Average  of  9  may  be  specified. 

4  and  over,  not  over  10  per  cent  4-  and  5-foot  lengths. 
Average  of  11  may  be  specified. 


156 


WOODEN  BOX  AND    CRATE   CONSTRUCTION 


Beech 


ITEM 


National  Hardwood  Lumber  Association 
American  Hardwood  Manufacturers'  Association 


Box  grades 


Higher  grade 
Lower  grade 
Thicknesses 
Widths,  inches 
Lengths,  feet 


No.  2  common. 

Pieces  3  to  7  inches  wide,  4  to  10  feet  long  must  work  50 
per  cent  clear  face  in  not  over  three  cuttings;  pieces  3  to 
7  inches  wide,  11  feet  and  over  long  must  work  50  per 
cent  clear  face  in  not  over  four  cuttings;  pieces  8  inches 
and  over  wide,  4  to  9  feet  long  must  work  50  per  cent  clear 
face  in  not  over  three  cuttings;  pieces  8  inches  and  over 
wide,  10  to  13  feet  long  must  work  50  per  cent  clear  face 
in  not  over  four  cuttings;  pieces  8  inches  and  over  wide, 
14  feet  and  over  long  must  work  50  per  cent  clear  face  in 
not  over  five  cuttings. 

No  cutting  to  be  considered  which  is  less  than  3  inches 
wide  by  2  feet  long. 

Wormy  beech. 

Shall  be  graded  according  to  the  rule  for  beech  No.  2  com- 
mon and  better,  with  the  exception  that  pin  worm  holes 
shall  not  be  considered  a  defect. 

No.  1  common. 
No.  3  common. 
See  Table  9. 

3  and  over.     Average  of  7  may  be  specified. 

4  and  over,  not  over  10  per  cent  4-  and  5-foot  lengths. 
Average  of  11  may  be  specified. 


APPENDIX 


157 


Tupelo  and  black  gum 


ITEM 


National  Hardwood  Lumber'Association 

American  Hardwood  Manufacturers'  Association 

Southern  Cypress  Manufacturers'  Association,  New  Orleans,  La. 


Box  grades 


Higher  grade 
Lower  grade 
Thicknesses 
Widths,  inches 
Lengths,  feet 


No.  2  common. 

There  is  no  restriction  as  to  heart  in  No.  2  common  tupelo. 

Sound  discolored  sap  is  no  defect. 

Pieces  3  to  7  inches  wide,  4  to  10  feet  long  must  work  50 
per  cent  sound  in  not  over  three  cuttings;  pieces  3  to  7 
inches  wide,  11  feet  and  longer  must  work  50  per  cent 
sound  in  not  over  four  cuttings;  pieces  8  inches  and  over 
wide,  4  to  9  feet  long  must  work  50  per  cent  sound  in  not 
over  three  cuttings;  pieces  8  inches  and  over  wide,  10  to 
13  feet  long  must  work  50  per  cent  sound  in  not  over  four 
cuttings;  pieces  8  inches  and  over  wide,  14  feet  and  over 
long  must  work  50  per  cent  sound  in  not  over  five  cuttings. 

No  cutting  to  be  considered  which  is  less  than  3  inches 
wide  by  2  feet  long. 

No.  1  common. 
No.  3  common. 
See  Table  9. 

3  and  over.     Average  of  7  may  be  specified. 

4  and  over,  not  over  10  per  cent  4-  and  5-foot  lengths. 
Average  of  10  may  be  specified. 


158 


WOODEN   BOX   AND   CRATE   CONSTRUCTION 


Oak  (plain,  red,  or  white) 


ITEM 


National  Hardwood  Lumber  Association 
American  Hardwood  Manufacturers'  Association 


Box  grade 


Higher  grade 
Lower  grade 
Thicknesses 
Widths,  inches 
Lengths,  feet 


No.  2  common. 

Pieces  3  to  7  inches  wide,  4  to  10  feet  long  must  work  50 
per  cent  clear  face  in  not  over  three  cuttings;  pieces  3  to 
7  inches  wide,  11  feet  and  longer  must  work  50  per  cent 
clear  face  in  not  over  four  cuttings;  pieces  8  inches  and 
over  wide,  4  to  9  feet  long  must  work  50  per  cent  clear 
face  in  not  over  three  cuttings;  pieces  8  inches  and  over 
wide,  10  to  -13  feet  long  must  work  50  per  cent  clear  face 
in  not  over  four  cuttings;  pieces  8  inches  and  over  wide, 
14  feet  and  over  long  must  work  50  per  cent  clear  face  in 
not  over  five  cuttings. 

No  cutting  to  be  considered  which  is  less  than  3  inches 
wide  by  2  feet  long. 

No.  1  common. 
No.  3  common 
See  Table  9. 

3  and  over.     Average  of  7  may  be  specified. 

4  and  over,  not  to  exceed   10  per  cent  of  4-  and  5-foot 
lengths.     Average  of  10  may  be  specified. 


APPENDIX 


159 


Balsam  fir 


ITEM 

Northern    Pine     Manufacturers' 
Association 

New  England  balsam  fir 

May  be  purchased  with  white 
pine. 

Usually  sold  with  spruce. 

160 


WOODEN   BOX  AND    CRATE   CONSTRUCTION 


Cypress 


ITEM 


National      Hardwood 
Association 


Southern    Cypress    Manufactur- 
Lumber  ers'  Association 

American    Hardwood    Manufac- 
turers' Association 


Box  grades 


No.  1  boxing. 


Higher  grade 
Lower  grade 

Thicknesses, 
inches: 
Rough 
SIS 

S2S 
Widths,  inches 


Length,  feet 


Must  work  66%  per  cent  in 
cuttings  containing  not  less 
than  72  square  inches.  No 
cutting  considered  which  is 
less  than  18  inches  long  or 
less  than  3  inches  wide. 

Each  cutting  may  contain 
sound  stain,  pin  worm  holes, 
unsound  knots  and  peck  that 
do  not  extend  through  the 
piece,  season  checks,  and 
other  defects  that  do  not 
prevent  the  use  of  the  cut 
ting  for  boxing  purposes. 

No.  2  boxing. 

This  grade  may  contain  all 
lumber  not  admitted  in  No. 
1  boxing,  but  each  piece  must 
work  at  least  50  per  cent  in 
the  same  size  cuttings  de- 
scribed in  No.  1  boxing. 

No.  2  common. 
Peck. 


Same  as  for  hardwoods. 
See  Table  9. 


Random  widths  3  and  over. 
Average  of  7  may  be  specified. 


No.  1  boxing,  6  and  over. 
No.  2  boxing,  4  and  over. 

Equal    proportions    may   be 

specified. 


Box. 

Each  piece  must  contain  66% 
per  cent  or  more  of  sound 
cuttings,  no  single  cutting  to 
contain  less  than  72  square 
inches.  No  piece  of  cutting 
may  be  shorter  than  2  feet 
or  narrower  than  3  inches. 
Sound  cuttings  will  admit  all 
the  defects  allowed  in  No.  1 
common.  The  waste  ma- 
terial may  be  thin  or  abso- 
lutely worthless. 


No.  2  common. 
Peck. 


I,  1M,  1^,2. 
%,  1H,  1**,  Ifc- 

Same  as  SIS. 

Random  widths  3  and  wider. 
Average  of  7  may  be  specified 
S1E,  %  off;  S2E  Y2  off. 

6  to  20.  Average  of  12  may 
be  specified. 


APPENDIX 


161 


Chestnut 


ITEM 


National  Hardwood  Lumber  Association 
American  Hardwood  Manufacturers'  Association 


Box  grades 


Higher  grade 
Lower  grade 
Thicknesses 
Widths,  inches 

Lengths,  feet 


No.  2  common. 

Pieces  3  to  7  inches  wide,  4  to  10  feet  long  must  work  50 
per  cent  sound  in  not  over  three  cuttings;  pieces  3.  to  7 
inches  wide,  11  feet  and  over  long  must  work  50  per  cent 
sound  in  not  over  four  cuttings;  pieces  8  inches  and  over 
wide,  4  to  9  feet  long  must  work  50  per  cent  sound  in  not 
over  three  cuttings;  pieces  8  inches  and  over  wide,  10  to 
13  feet  long  must  work  50  per  cent  sound  in  not  over  four 
cuttings;  pieces  8  inches  and  over  wide,  14  feet  and  over 
long  must  work  50  per  cent  sound,  in  not  over  five  cuttings. 

No  cutting  to  be  considered  which  is  less  than  3  inches 
wide  by  2  feet  long. 

Sound  Wormy 

Worm  holes  admitted  in  this  grade  without  limit. 

No  piece  shall  contain  heart  to  exceed  %  its  length  in  the 
aggregate. 

Pieces  4  inches  wide,  6  and  7  feet  long  must  be  sound;  8  to 
11  feet  long  must  work  66%  per  cent  sound  in  not  over 
two  pieces;  12  feet  and  over  long  must  work  66%  per  cent 
sound  in  not  over  three  pieces.  No  piece  of  cutting  to  be 
less  than  2  feet  long  by  the  full  width  of  the  piece. 

Pieces  5  inches  and  over  wide,  6  to  11  feet  long  must  work 


per  cent  sound  in  not  over  two  pieces;  12  feet  and 
over   long   must  work 


per  cent  sound  in  not  over 
three  pieces. 

No  piece  of  cutting  considered  which  is  less  than  4  inches 
wide  by  2  feet  long  or  3  inches  wide  by  3  feet  long. 

No.  1  common. 
No.  3  common. 
See  Table  9. 

No.  2 — 3  and  over.    Sound  wormy,  4  and  over.    Average 
of  8  may  be  specified. 

No.  2 — 4  and  over,  not  to  exceed   10  per  cent  of  4-  and 

5-foot  lengths. 
Sound  wormy,  6  and  over,  not  to  exceed  10  per  cent  of 

6-  and  7-foot  lengths.     Average  of  11  may  be  specified. 


Sugar  pine 

Same  as  western  yellow  pine  (California  white  pine)  on  page  148  under 
rules  of  California  White  and  Sugar  Pine  Association. 


162  WOODEN  BOX  AND  CRATE  CONSTRUCTION 


PLATE  I — Defects  recognized  in  the  commercial  grading  of  lumber. 


APPENDIX 


Standard  knot 


Large  knot 


Encased  knot 


Spike  knot 


Shake 


Checks 


Pitch  pocket 
Upper:  Edge-grain 

Pitch  pocket 
Lower:  Flat-grain 


Pitch  stre; 


Stained  sap 


Water  stain 


Mineral  streaks 


Gum   spots 


Bird  pecks 


Rot 


Shot-worm  holes 
Grub-worm  holes 


Rafting-pin  hole 
Knot  hole 


Wane 


Loosened  grain 


Insufficient     thickness 
Chipped  grain 


Method   of   measuring 

knots 

"A"    is    the     effective 
diameter 


164 


WOODEN    BOX   AND    CRATE    CONSTRUCTION 


PW 


PLATE  II 


FIG.   1 
White  Oak 

A  hardwood  show- 
ing: V,  vessels  or 
pores;  TY,  tyloses 
in  a  vessel;  P,  par- 
enchyma cells.  The 
dark  areas,  F,  wood 
fibers;  MR,  medul- 
lary ray. 


FIG.  2 
Shortleaf   Pine 

A  c  o  n  i  f  erous 
wood  showing:  T, 
tracheids,  which 
comprise  the  bulk 
of  the  wood;  RD, 
resin  duct;  MR, 
medullary  ray. 


APPENDIX  165 


PLATE  II — Cubes  of  wood  magnified  about  25  diameters. 

FIG.  1— White  oak. 

FIG.  2 — Shortleaf  pine. 

In  each  cube  the  top  view  represents  the  transverse  or  end  sur- 
face, the  left  view  the  radial  or  "quartered"  surface,  and  the  right 
view  the  tangential  or  plain-sawed  surface.  (SPW)  springwood ; 
(SUW)  summerwood. 

The  medullary  rays  are  continuous  from  the  starting  point  to  the 
bark,  and  the  vessels  are  continuous  longitudinally,  although  the 
illustrations  show  them  interrupted. 


166  WOODEN  BOX  AND    CRATE   CONSTRUCTION 


PLATE  III — Styles  of  wooden  boxes,  nailed  and  lock-corner  construction. 


APPENDIX 


167 
PLATE  III 


Alternate 


Sfy/c  6 


168  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


PLATE  IV — Special  styles  of  boxes. 

FIGS.  1  and  3 — Boxes  made  for  easy  opening. 
FIG.  2 — An  accessible  box  (cover  screwed  on  and  sealed  with  wax) 
FIG.  4 — Modified  Style  2  box  adapted  to  be  closed  without  nailing. 
FIG.  5 — Modified  Style  4  box  adapted  to  be  closed  without  nailing. 


APPENDIX 


169 


PLATE  IV 


FIG.   5 


170  WOODEN  BOX  AND    CRATE   CONSTRUCTION 


PLATE  V — Strapped  boxes. 

FIG.  1 — Reinforced   battens. 

FIG.  2 — End-opening  box,  cover  held  only  by  strapping. 

FIG.  3 — Double  corner  nails  to  keep  the  straps  in  position  if  shrinkage 

occurs. 
FIGS.  4  and  5 — Common  methods  of  box  strapping. 


APPENDIX 


171 


PLATE  V 


FIG.  4 


FIG.  5 


172  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


PLATE  VI— Types  of  handles. 

FIG.  1 — Handhold  for  boxes  in  which  the  opening  is  not  objectionable. 
FIG.  2 — Section  of  a  box  end  with  handhold  formed  by  beveling  the 

edge  of  cleat. 
FIG.  3 — Handhold    for    boxes    of    medium    weight    that    need    to    be 

handled  with  care. 
FIG.  4^— Method  of  attaching  rope  handles. 

Right — Outside  end  of  box. 

Left — Reverse  side  of  cleats. 
FIG.  5 — Method  of  attaching  webbing  handles. 

Upper — Outside  face  of  end. 

Lower — Inside  face  of  end. 
FIG.  6 — Another  method  of  attaching   webbing  handles. 

Left — Outside   face  of  end. 

Right — Inside  face  of  end. 


APPENDIX 


173 
PLATE  VI 


FIG.   5 


FIG.  3 


FIG.  6 


174  WOODEN  BOX   AND    CRATE   CONSTRUCTION 


PLATE  VII — Different  types  of  corner  construction. 
FIG.  1 — Details  of  dovetail  corner. 
FIG.  2 — Dovetail  box  corner. 
FIG.  3 — Test  specimens  for  determining  holding  power  of  nails  parallel 

with  and  at  an  angle  to  grain. 
FIG.  4 — Joints  for  4-one  box  cleats. 

Upper — Mortise  and  tenon. 

Lower — Step  mitre. 


APPENDIX 


175 


PLATE   VII 


FIG.  1 


FIG.  3 


v 


FIG.  2 


FIG.  4 


176  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


PLATE  VIII — Wirebound  boxes. 

FIG.  1 — Fassnacht    box — note    method    of    joining    the    wires    at    the 

corners. 
FIG.  2 — Method  of  reinforcing  battens,  (c)  Regular  cleats  with  mortised 

and  tenoned  joints,    (b)    Battens,    (n)   Cement-coated   (7d)   nails. 
FIG.  3 — "4-one"    wirebound   box    closed    for    shipment.      Note    position 

and  character  of  twists  for  uniting  the  binding  wires.' 
FIG.  4 — The  outer  surface  of  a  mat  for  a  "4-one"  box. 
FIG.  5 — "4-one"  box  with  inside  liners  or  corner  cleats. 
FIG.  6 — "4-one"  wirebound  box  assembled. 


APPENDIX 


177 


PLATE  VIII 


FIG.  6 


178  WOODEN    BOX    AND    CRATE    CONSTRUCTION 


PLATE  IX — Types  of  commercial  boxes. 

FIG.  1— Phonograph  box  made  of  plywood  fastened  to  a  frame. 

FIG.  2— Egg    crate    with    sides,    top,    and    bottom    made    of    rotary -cut 

veneer. 

FIG.  3 — Apple  box. 
FIG.  4 — Orange  case. 
FIG.  5 — Upright  piano  box. 


APPENDIX 


179 


PLATE  IX 


FIG.  1 


FIG.  4 


FIG.  ; 


180  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


PLATE  X — Types  of  plywood  or  veneer  panel  boxes. 

FIG.  1 — This    box   corresponds    in    some    points    of    construction    with 

Style  3  of  nailed  box. 
FIG.   2 — Corresponds    in    some    respects   with   hardware   type    (Fig.    3) 

shown  in   Plate  XIV. 

FIG.  3 — Corresponds  most  closely  to  Style  2  of  nailed  box. 
FIG.  A — This  box  has  double  number  of  cleats  of  box  shown  in  Fig.  2 

but  is  otherwise  similar  in  construction. 


APPENDIX 


PLATE  X 


FIG.  3 


182  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


PLATE  XI — Three-way  crate  corners. 

FIG.  1 — Three-way  crate  corner  made  of  2§<s  by  3^4  inch  stock. 

FIG.  2 — Three-way  crate  corner  made  of  2  by  6  inch  stock. 

FIG.  3 — Three-way  crate  corner  made  of  2^  by  3?4  inch  stock. 

FIG.  4 — Method   of  cutting  and  nailing  a  diagonal   brace. 

FIG.  5 — A  common  style  of  crate  corner. 

FIG.  6^A  style  of  crate  corner  consisting  of  the  corner  as  shown  in 

Fig.  5   with  one  double   member. 
FIG.  7 — One  method  of  reinforcing  a  crate  corner. 


APPENDIX 


183 


PLATE  XI 


FIG.  4 


FIG.  7 


184  irOODEN   BOX   AND    CRATE    CONSTRUCTION 


PLATE  XII — Various  arrangements  of  crate  members  at  three-way  corner. 


APPENDIX 


185 


PLATE   XII 


H 


M 


N 


186  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


PLATE  XIII — Crates  with  special  features. 

FIG.  1 — Several  sets  of  cross-bracing  and  cross-members  used  to  in- 
crease rigidity  and  bending  strength. 

FIG.  2 — The  scabbing  shown  inside  the  vertical  members  extends  to  the 
outer  edges  of  the  top  and  bottom  horizontal  crate  members. 

FIG.  3 — Framework   of   crate   to   which   all   other   parts    are    fastened. 

FIG.  A — Crate  with  3-way  corner  construction  showing  cross-bracing, 
diagonal  bracing,  and  extra  pieces  to  strengthen  the  skids  which 
support  the  vertical  members. 


APPENDIX 


187 


PLATE  Xll.1 


FIG.  3 


FIG.  4 


188  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


PLATE   XIV — Method   of   numbering   faces   of   test   boxes   and   crates    for 
convenience  in  recording  data  and  location  of   failures. 

FIGS.  1  and  2 — Crate  numbering  system. 
FIGS.  3  and  4— Box  numbering  system. 


APPENDIX 


189 


PLATE   XIV 


FlG.   3 


190  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


PLATE  XV — Different  kinds  of  joints  and  fasteners. 

FIG.  1 — Use  of  corrugated  fasteners. 

FIG.  2 — Different  types  of  corrugated  fasteners. 

FIG.  3 — Dovetail  joint. 

FIG.  A — Coil  of  corrugated  fastening  material. 

FIG.  5 — Lock-corner  joint. 

FIG.  6 — Lap  joint. 


APPENDIX 


191 


PLATE  XV 


FIG.  1 


-a- 


FIG.  4 


FIG.  6    m 


192  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


PLATE  XVI— Hardwoods  with  pores. 

Ring-porous  hardwoods,  figures   1-9  inclusive, 
Summerwood  with  radial  figure,  figures  1-3. 
Summerwood  with  tangential  figure,   figures  4-8. 
Summerwood  without  special  figure,  figure  9. 

Diffuse-porous  hardwoods,   figures   10-12  inclusive, 
Pores  easily  visible  to  naked  eye,  figure  10. 
Pores  barely  visible  to  naked  eye,  figures  11-12. 


FIG.  1 — A   red   oak. 


APPENDIX 


FIG.  2 — A  white  oak. 


193 
PLATE  XVI 


FIG.  3 — Chestnut. 


FIG.  4 — White   elm.  FIG.  5 — Cork  or  rock  elm.  FIG.  6 — Slippery   elm. 


FIG.    7 — Hackberry. 


FIG.  8 — A  white  ash. 


FIG.  9— Black   ash. 


FIG.  10 — Butternut 


FIG.  11 — Birch. 


FIG.  12 — Cottonwood. 


194  WOODEN   BOX   AND    CRATE    CONSTRUCTION 

PLATE  XVII 


FIG.  1 — Yellow  poplar.  FIG.  2 — Black    gum.  FIG.  3 — Aspen,  or  "pop- 

ple." 


FIG.  4 — Buckeye. 


FIG.  5 — Ripple  marks 
on  tangential  surface 
as  in  buckeye. 


FIG.  6 — Sycamore. 


FIG.  7— Beech. 


FIG.  8 — Red  gum. 


FIG.  9— Soft  maple.  FIG.  10— Hard  maple 


FIG.  11 — Basswood. 


APPENDIX  195 


PLATE  XVII — Diffuse-porous  hardwoods. 

The  pores  in  these  woods   are  not  readily  visible  to  the  naked  eye. 
The  rays  vary  in  size : 
Conspicuous  in  figures  6  and  7 
Not  conspicuous  but  visible,  figures  1,  8,  9,  10  and  11. 
Not  distinctly  visible  figures  2,  3,  4. 


196  WOODEN   BOX   AND    CRATE   CONSTRUCTION 


PLATE  XVIII — Softwoods,  conifers,  or  woods  without  pores  or  vessels. 

Woods  without  resin  ducts,  figures  1-6. 
Woods  with  resin  ducts,  figures  7-12. 


APPENDIX 


197 
PLATE  XVIII 


Frc.  1— Port    Orford 
cedar. 


FIG.  2 — Western    red 
cedar. 


FIG.  3 — Cypress. 


FIG.  4 — True  fir. 


FIG.  5 — Hemlock. 


FIG.  6 — Redwood. 


FIG.  7 — White  pine. 


FIG.  8 — Western     yel- 
low pine. 


FIG.  9 — Southern    y  e  1 
low   pine. 


FIG.  10 — Douglas  fir. 


FIG.  11 — Larch. 


FIG.  12 — Spruce. 


198  WOODEN   BOX   AND   CRATE   CONSTRUCTION 


PLATE  XIX 


FIG.  1 — Sitka  spruce 


FIG.  2 — Douglas  fir. 


APPENDIX  199 


PLATE  XIX — Split  tangential  surfaces  of  Sitka  spruce  and  Douglas  fir. 

Note  the  "pocked"  or  "dimpled"  appearance  of  the  spruce,  not  found  in 
Douglas  fir.  This  characteristic  is  most  pronounced  in  Sitka 
spruce  with  narrow  rings,  and  is  almost  entirely  absent  in  very 
wide-ringed  material. 


INDEX 


A 


Air-drying    of, lumber.      As    decay 
preventive,  32,  36 

time  necessary  for,  36 
Allowance  for  shrinkage,  17 
Alpine  fir.    Identification,   136 
Annealed  strapping,  60 
Annual  rings,  110 
Appalachian      spruce.       Rules      for 

grading,  145 

Arborvitae.    Structure,  122 
Army  ordnance  boxes,  43 
Ash.    Identification,   127 

structure,   119 

see  also  Black  ash;  Green  ash; 
Pumpkin    ash ;    White    ash 
Aspen,  see  Popple 
Assembling  of  wirebound  boxes,  105 

with  detached  tops,  107 

with  wedgelock  ends,  107 
Association  grading  rules,  11 
Availability  of  box  lumber,  1,  41 

B 

Balanced  construction,  43 

how  determined,  87 

relation    to   nailing   qualities    of 
wood,  51,  53 

spacing  of  nails  in,  55 
Bald  cypress.     Identification.  135 
Balsam  fir.     Identification,  136 

rules  for  grading,  159 
Barbed  nails,  55 
Basswood.     Identification,  131 

rules    for   grading,    155 

structure,  121 
Battens.     In  crates,  81 

in  wirebound  boxes,  68,   107 

use  in  strapping,  61 
Beech.     Identification,  130 

rules  for  grading,  156 

structure,   120 
Binding  rods  in  crates,  84 
Binding  wire   for  wirebound  boxes, 

105 
Birch.    Identification,  128 

rules   for  grading,    154 

structure,   121 
Bird  pecks,  10 

200 


Black  ash.     Identification,  127 

structure,  119 
Black  gum.     Identification,  131 

rules   for  grading,    157 

structure,  122 
Blemishes  in  lumber,  8 
Blue  stain,  31,  110 
Bolting  qualities   of   wood,   81 
Bolts.     Carriage,  83 

machine,  84 

use  in  crates,  83 
Bored  holes  for  nails.     Effect,  83 

for  lag  screws,  84 
Bow,  10 
Box  design,  40,  balance   in   43 

characteristic  of  various  styles, 
64 

defined,  40 

factors  determining  size,  73 

factors  determining  strength  re- 
quired, 70 

factors  influencing  details,  40 

limitations  by  traffic  rules.,  74,  85 

of  boxes  with  detached  tops,  107 

of  hinged  boxes,  62 

of   wirebound  boxes,    103 

one-piece  parts,  44 

relation  to  available  equipment, 
42 

relation  to  strapping,  61 

relation  to  wood  groups,  103 

special   constructions,  74 

with   wedgelock   ends,   105 
Boxes.    Salvage  value,  1 

second  hand,   2 
Box  nails,  53,  101 
Box  styles,  42 

Box  lumber,  see  Lumber;  Woods. 
Braces.    Fitting  and  fastening,  80 

internal,  84 

use  on  long  crates,  79 
Buckeye.    Structure,  122 

see  also  Yellow  buckeye 
Butt  joint,  44 
Butternut.    Identification,   128 

structure,  120 


California    white    pine,    see    Yellow 
pine 


INDEX 


201 


Canned   foods  boxes.    Specifications, 

103 
Carolina  pine,   see   Southern  yellow 

pine. 

Carriage  bolts  in  crating,  83,  84 
Case  hardening  of  lumber,  25,  31 
Cedar.    Identification,  132 

structure,    122 

see  also  Northern  white  cedar ; 
Port     Orford     cedar;     Red 
cedar;  Western  red  cedar 
Cells  in  boxes,  74 
Cement-coated  nails,   55,    101 

use  in  wirebound  boxes,  106 
Checks,  9,  25,  31 

effect  on  strength  of  box,  50 

use  of  corrugated  fasteners,  45, 

50 
Chestnut.    Identification,   127 

rules   for   grading,    161 

structure,  118 

Classifications,  Freight,  limiting  de- 
sign, 74 
Cleats.    On  standard  styles,  65 

on  wirebound  boxes,  68,  105 
Clinching  of  nails,  56 
Closing    wirebound   boxes,    106,    107 
Collapse  of  wood  cells  in  drying,  23, 

31 

Color  of  wood,  25,  109 
Compartment  boxes,  24 
Compression-cornerwise  test,  96 
Compression-on-faces  test,  96 
Compression-on-an-edge   test,   92 
Compression    strength    of    wood,    26 

in  crates,  78 
Conifers.    Description,    132 

identification,   122 

structure,  114 
Construction.    Width  of   pieces,    101 

of  wirebound  boxes,  104 
Contents.        Determining      size      of 
boxes,  73 

effect  on  required  strength,  70 

nesting,  disassembling  or  knock- 
ing down,  73 

protection  from  the  elements,  81 

protection    of    fragile    contents, 

74 

Cork  elm,  see  Rock  elm 
Corner  irons,  62 
Corner  construction  of  boxes,  66 
Corner  construction  of  crates,  77 
Corrugated  fasteners,  44,  45,  50,  101 


Cost.    Air  drying,  37 

of  boxes  in  relation  to  use  of  re- 
inforcements,  45 

of  box  lumber,  1 

of  box  lumber  in  relation  to  sal- 
vage, 42 

of  factory  operation,  42 

of  kiln-drying,  37 
Cotton  gum.     Identification  131 
Cottonwood.     Identification,  129 

rules  for  grading,  149 

structure,   120 
Crates.    Bracing,  79 

corner  construction,  77 

design,  77 

effect  of   physical   properties  of 
wood,  81 

factors      determining     strength 
required,   85 

factors  affecting  strength,  77 

factors  influencing  size,  86 

fastenings,  82 

frame  members,  78 

reinforcements,  82 

scabbing,  80 

sheathing,  81 

skids,  79 
Crook,  10 

Cross  bracing  in  crates.    Rules,  80 
Cross-grain.    Effect  on  strength,  51 
Crushing  resistance  of  wood,  26 
Cucumber.    Identification,   131 

structure,  121 
Cupping,  10,  16,  25,  31 

plywood,  39 
Cushioning   material    for    protecting 

contents,  74 
Cutting  of  veneer,  37 
Cypress.    Rules  for  grading,  160 

structure,   126 

see  also  Bald  cypress 

D 

Decay,  31 

Defects  in  lumber.    Defined,  8 

effect  on  strength  of  box,  48 

effect  on  strength  of  crate,  81 

specifications,  99 
Density  of  wood,  15 

relation  to  design,  45 

relation    to    nail-holding    power, 
51 

relation  to  size  of  nail  head,  57 

relation  to  spacing  of  nails,  56 
Design.     Efficiency   shown   by  tests, 
87 

see  Box  design ;  Crate  design 
Detached   tops   in   wirebound   boxes, 
107 


202 


INDEX 


Deterioration    in    stored    lumber,    31 

Diagonal  nailing,  53 

Diffuse-porous  woods,  112,  128 

Direction    of    grain.      How     deter- 
mined,   114 

Directions   for  nailing,   55 
in  crates,  82 

Disassembling  of  contents  for  ship- 
ment, 73 
in  crates,  86 

Displacement.      Importance    in    ex- 
port  shipments,   73 

Dote,  9 

Dovetail  boxes,  67 

Douglas  fir.     Identification,   134 
structure,   124 

Douglas   spruce.    Structure,    124 

Drop-cornerwise  test,  92 

Drop-edgwise  test,  92 

Drum  test,  91 

Dry  rot.     Prevention,  32 

Drying,  sec  Seasoning 


Eastern    white    pine.     Identification, 

133 

Elm.    Identification,  127 
structure,  119 
see    also    Rock    elm ;     Slippery 

elm ;  Soft  elm 
Engelmann     spruce.       Identification, 

134 

Equipment.     Box  making,  42 
Export  containers.     Nailing,  55 
strength    requirements,    72 
strength  requirements  of  crates, 

85 
woods  not  to  be  used,  32 


Fassnacht  type  of  box.     Battens,  69 
Fastenings  and  reinforcements.  Cor- 
ner irons,  62 

crate,  82 

hand-holds,  62 

handles,  62 

hinges,  62 

metal  handles,  64 

nails,  53 

rope  handles,  63 

screws,  59 

staples,  59 

webbing  handles,  63 
Fiber-saturation   point,   16,  20 
Fiber,  Wood,  113 


Fir.  Identification,   136 

structure,  126 

see  also  Alpine  fir ;  Balsam  fir ; 
Douglas  fir;  Noble  fir;  Red 
fir,  White  fir 

"Flotation."    Method  of  packing,  74 
Foundations    and    skids    in    lumber 

yard,  35 

4-One- boxes,  see  Wirebound  boxes. 
Fragile  contents.     Protection,  74 
Frame  members  of  crates,  78 

skids,  79 
Fungous  growth  in  lumber,  31 

stain,  110 
Fusiform   rays,    114 


Grades    of    lumber.     According   to 

size,    10 

association  rules,   11 
how  determined,  8 
rules  for  rotary  cut,  137 
suitable  for  boxes  and  crates,  11 

Green   ash.    Identification,    127 
structure,   119 

Grouping  of  woods,  100 

for  wirebound  boxes,  104 

Gum,  sec  Black  gum  ;  Cotton  gum  ; 
Red  gum 

Gum  spots,  10 


H 


Hackberry.     Identification,   127 

structure,   118 
Hand-holds,  62 
Handles,  62 
Hard   maple.     Identification,   130 

structure,  121 
Hardness  of  wood,  30 
Hardware  type  of  box,  66 
Hardwood.     Identification,   117 

structure,   112 

use   in  boxes,   126 

Hazards    of    transportation.      Effect 
on  box  design,  71 

effect  on  crate  design,  85 

export  shipping,  72 
Heartwood.     Construction,   109 
Hemlock.    Identification,   136 

rules  for  grading,  151 

structure,   126 

see  also  Western  hemlock 
Hinges,   62 
Holding  power  of  nails,  55 

sec  also  Nail  holding  power  of 

wood 
Honeycombing  of  lumber,  25,  31 


INDEX 


203 


I 


Identification   of  woods,   108 

key,  117 

procedure,   115 

wood  structure,  109 
Insect  attack  on  lumber,  32 

effect  on  strength  of  box,  51 
Internal  bracing,  sec  Bracing 
Interstate  Commerce  Commission,  74 


Jack  pine.     Structure, -123 
Joints,  43 

butt,  44 

Linderman,  44 

matched,  44 

serviceability    of    nailed    joints, 

specifications,  101 
strength    affected    by    overdriv- 
ing nails,  58 
width,  43 
wirebound  box,  68 


K 


Kiln-drying  of  wood,   16,  36 

collapse  of  wood,  23 

objections  to  kiln-drying,  22 

to  avoid  stain,  31 
Knots.     Defined,  9 

effect  on  strength,  44,  48 

kinds,  9 


Lag  screws.     Use  in  crates,  84 
Larch.    Structure,   124 
Linderman  joint,  44,   101 
Liner  for  boxes.     Sheet  metal,  74 

vermin,    76 

water-proof   paper,    74 
Lock-corner  style  of  box,  66 

specifications,   103 
Locks,  62 

Lodgepole  pine.     Structure,   123 
"Log  run,"  11 
Lumber.    Case  hardening,  25,  31 

checking,  25,  31 

collapse  of  wood   cells   in   kiln- 
drying,  23,  31 

color,  25 

consumption  by  States,  5 

cross-grain,  51 
'  cupping,  10,  16,  25 

decay,  31 

defects,  8,  48 


deterioration  in  storage,  31 

grades,   8 

grading  rules,  141 

honeycombing,  25,  31 

kiln-drying,    16,   31 

insect   attack,  32 

moisture  content,  17 

see    Moisture   content 

piling  in  yard,  32,  35 

plywood,  39 

printing,  25 

resawing,  10 

rot,  31 

rules  for  grading,  141 

salvage  value,  1 

seasoning  in  storage,  30 

shearing,   132 

shrinking,  16,  22 

sizes,  8 

specifications  of  National  As- 
sociation of  Box  Manufac- 
turers, 99,  103 

stain  prevention,  3\ 

standard  defects,  8 

standard  sizes,  8,  10 

storage,  30 

storage    deterioration,    31 

swelling,   16,  22 

swelling  avoided,   23 

thickness  of  wood  in  relation  to 
size  of  nail  head,  57 

thickness  of  wood  in  relation 
to  use  of  strapping,  61 

twisting,  31 

veneer,  37 

warping,  16 

waste  in  manufacturing,  11 

width,  43 

see  also  Woods 
Lumber  yard.    Methods  of  piling,  33 

drainage,  33 


M 


Machine  bolts  in  crates,  84 
Magnolia.    Structure,   121 
Manufacturing.     Cost   of    operation, 
42 

equipment,  42 

limitation,  42 

poor,  10 

styles  of  boxes,  42 
Maple,  see  Hard  maple ;  Soft  maple. 
Matched  joint,  44 
Material.     Specifications,  99 

in  wirebound  boxes,  104 
Mechanical    properties    of    wood,    26 
Medullary  rays,  113 


204 


INDEX 


Metal  binding.    Application,  60 

effect  on  box  shrinkage,  47 

effect  on  box  strength,  60 

for  wirebound  boxes,  105 

in  crates,  84 

nails,  60 

purposes,  60 

staples,  59 

time  to  apply,   48 

types,  60 

Metal  handles,  64 
Metal  liner  for  boxes,  74 
Modulus  of  rupture,  29 
Modulus  of  elasticity,  30 
Moisture.     How  contained  in  wood, 
16 

fiber  saturation  point,  16 
Moisture  content 

affecting  freight  charges,  30 

effect  in  crates,  81 

effect  on  box  strength,  47 

how  determined,   15 

how    effect    on    boxes    is    deter- 
mined, 87 

importance,   15 

proper,   17,  47 

specifications,   99 

variation,  16,  22 

Mortise     and    tenon     in    wirebound 
boxes,  68 


N 


Nailed  boxes,  64 
Nail  holding  power  of  wood,  30 
affected  by  density  of  wood,  53, 

65 

affected  by  design  of  nail,  53 
affected  by  moisture  content,  15, 
47 

affected  by  size  of  nail  head, 
57 

tests,  53 

Nailing.    Effect  on  box  strength,  91 
Nailing  in  wirebound  boxes,  106 
Nailing  of  crates.    Size  and  spacing 

of  nails,  82 
three-way  corner,  77 
Nailing     and     bolting     qualities     of 

wood,  81 

Nailing   of   wooden    boxes.     Clinch- 
ing,  56 
directions,  55 
overdriving,  30,  58,  102 
side,  56 
specifications,   101 


Nailing    qualities    of    wood.      Diag- 
onal nailing,  53 

effect   on   box   strength,    51 

end  grain  and  side  grain,  64 

factors   affecting,    51 

in  crates,  81 

Nailless    straps,    sec    Metal    binding 
Nails.    Barbed,  55 

box,   53 

cement-coated,  55 

clinching,  56 

crate,  82 

effect    of    design     of     nails     on 
holding  power,  53 

effect  of  size  of  head,  57 

overdriving,  30,  58 

selection,   30 

size   in   crates,  82 

spacing,  55,  102 

spacing  in  crates,  55,  101 

strapping,  60 
Nesting  of  contents,  73 
Nets.     Use  in  export  shipping,  72 
New    England    spruce.      Rules    for 

grading,   145 
New    England    balsam.      Rules     for 

grading,  159 

Noble  fir.    Identification,  136 
Non-porous  wood,  114 
North    Carolina   pine,   sec    Southern 

yellow  pine 

Northern    white    cedar.     Identifica- 
tion, 132 
Norway  pine.     Identification,    134 

structure,   123 


0 


Oak.    Identification,  126 
rules  for  grading,  158 
structure,   118 

Odor  of  wood,  26 

in  identification,  116 

Ordnance  boxes,  43 

Oregon  pine.     Structure,  124 

Oven-dry  weight,   15 

Overdriving  of  nails,  30,  58,  102 


Packing  for   fragile  contents,  75 

Panel  boxes,  70 

Paper  liner.     Use  as  waterproofing, 

74 

Parenchyma  tissue,  113 
Partitions  in  boxes.  75 
Physical  properties  of  woods,  see 

Woods 


INDEX 


205 


Pilferage.    Protection   against,   76 
relation  to  fastenings,  59,  62 
sheathing     as     crate     protection 

against   stealing,   81 
strapping    as    pilferage    preven- 
tion for  boxes,  60 
Piling  lumber  in  yard.     Foundations 

and  skids,  35 
placing,  36 
proper  methods,  32 
size  and  spacing  of  piles,  36 
stickers,   35 
Pine.    Structure,  123 

white,   identification,   133 
rules  for.  grading,   141 
see    also    Eastern    white    pine ; 
Sugar  pine ;  Western  white 
pine 

yellow,    identification,    134 
rules    for   grading,    143 
see  also  Jack  pine ;   Lodge- 
pole    pine ;     Norway    pine ; 
Pitch     pine ;     Scrub     pine ; 
Yellow   pine 

Pitch  pine.     Structure,   123 
Pitch-pockets,  9,  115 
Pitch  streaks,  9,  115 
Pith,  9 

Pith-flecks,  113 
Plywood.    Use,  39 

in  panel  boxes,  70 
Poor  manufacture    of  lumber,  10 
Poplar,    yellow    (tulip).     Rules    for 

grading,  150 
structure,  121 
Popple.    Identification,   129 

structure,   122 
Pores.     Construction     in    hardwood, 

112 

in    identification,    116 
Port    Orford    cedar.     Identification, 

133 

structure,    122 
Powder  post  beetle,  32 
Printing  on  boxes,  25 

selection  of  wood,  30 
Protection  of  fragile  contents,  74 
Pumpkin  ash.     Identification,  127 

structure,   119 
Puncturing.     Infrequence    in    boxes, 

46 

plywood,  39 
resistance  of  panel  boxes,  70 

Q 

Quarter-sawed    lumber     for     special 

boxes,  23 
Quarter-sawing,   113 


R 


Rafting  pin  holes,  10 
Rays,  Fusiform,  114 

medullary,   113 
Red  cedar.    Structure,  122 
Red    cedar,    Western,    see    Western 

red  cedar 

Red    fir.    Identification,    136 
Red  gum.    Identification,  130 

rules  for  grading,  147 

structure,   121 
Red  oak.    Identification,   126 

rules  for  grading,  158 

structure,    118 

Red  spruce.    Identification,  134 
Redwood.    Identification,  135 

structure,  126 
Reinforcements,  53,  62 

bracing   long   crates,   79 

corrugated  fasteners,  44 

sec   also   Fastenings 
Resawing.    Box  lumber,  10 

into  veneer,   37 
Resin  content,  15 
Resin  ducts,  114 
Returnable  boxes,  43 

corner  irons,  62 

handles,  62 

Ring  porous  woods,  112 
Rings,  Annual,   110 
Rock  elm.    Identification,  127 

structure,   119 
Rods,  Binding,  84 
Rope  handles,  63 
Rot,  9,  31 

extent  permissible,  51 
Rotary-cut  lumber.     Drying,  36 

method  of  cutting,  37 

rules   for  grading,   137 

use  in  wirebound  boxes,  67 
Round-edge  lumber,  11 
Rust.    Treatment  of  metal  bindings, 
61 


Salvage  value  of  wooden  boxes.  1 
Sap  gum,  sec  Red  gum 
Sapstain,  31 

Sapwood.    Structure,  109 
Scabbing  in  crates,  80 
Schedule  of  nailing,  101 
Screws.    Advantages   and   disadvan- 
tages,  59 

use  of  lag  screws  in  crates,  84 
Scrub  pine.     Structure,   123 
Sealing  of  boxes,  59 


206 


INDEX 


Seasoning  of  lumber.    In  storage,  30 

to  avoid  stain,  31 

veneer,  38 

Second-hand  boxes.  Caution  in  use,  2 
Shake.    Effect   on    strength   of   box, 

9,  50 
Shearing,  22 

effect  of  strapping,  60 

resistance,  26 

resistance  of  crates,  79 
Shearing  strength  of  wood,  26 

affected  by  size  of  nail  head,  57 
Sheathing  in   crates,   81 
Sheet  metal  liner  for  boxes,  74 
Shiplap  joint,   44 
Shock  resisting  ability  of  wood,  22, 

30 
Shrinkage  of  wood,  16,  22 

allowance  for,  17 

how  avoided,  23 

plywood,  39 

vertical  cleats,  65 
Side  nailing,  56,   102 
Sitka   spruce.    Identification,    134 

rules  for  grading,  145 

structure,    124 
Size  of  box.     How  determined,  73 

traffic   limitations,   73 
Size  of  crate.     How  determined,  85 
Sizes  of  box  lumber,  8 
Skids  in  lumber  yard,  35 
Skids  on  crates,  79 
Slippery  elm.     Structure,   119 
Sodium   carbonate   as    stain    preven- 
tive, 31 

Soft  elm.    Rules  for  grading,  153 
Soft   maple.    Identification,    130 

rules   for  grading,    153 

structure,    121 
Softwood.     Structure,    114 
Southern    yellow    pine.      Identifica- 
tion, 134 

rules   for  grading,    143 

structure,   123 
Spacing  of  nails,  55,   102 

side,  56 
Spacing    of    staples     in     wirebound 

boxes,  106,  107 
Special   constructions,   74 
'  Species  of  box  wood.    Choice,  2,   14 

see  Lumber;   Woods 
Specifications.     4-One  boxes,   103 

grade  of  lumber,  11 

lock-corner   boxes,    103 

nailed  boxes,  99 

purpose,  97 

standardization        of        packing 

boxes,  98 
Specific  gravity  of  woods,   14 


Splines.    Use  in  trays,  76 
Splits,  9 

effect  on  box  strength,  45 

how  avoided  in  crates,  82 

in   plywood,   39 

relation  to  size  of  nails,  56 

relation  to  spacing  of  nails,  55 

use  of  corrugated  fasteners,  45, 

50 

Springwood,  110 
Spruce.    Identification,  134 

rules    for   grading,    145 

structure,  124 

see  also  Douglas  spruce  ;  Engel- 
mann  spruce  ;  Sitka  spruce  ; 
White    spruce ;    Red    spruce 
Staggered  nailing  in  crates,  82 
Stain,  9,  110 

prevention,  31,  36 
Standard  sizes  of  box  lumber,  8 
Standardization  of  design,  42 

of  boxes,  99 

styles  of  nailed  boxes,  64 
Staples,  59 

wirebound  boxes,  105 
Step-mitre  in  wirebound  boxes,  68 
Stickers   in  piled  lumber,  35 
Stiffness  of  wood,  30 

influence  on  box  strength,  45 

plywood,  39 

Storage.      Possible    deterioration    of 
lumber,  30 

proper  methods  of  piling,  32 

seasoning  of   lumber,  30 
Strapping,  see  Metal  binding. 
Strength     of     boxes.       Affected     by 
nailing,   91 

how  determined,  87 

relation  to  contents,  70 
Strength     of     crates.     Affected    by 
stiffness    of    wood,   45 

affected  by  reinforcements,  84 

affected  by   style,   77 

factors  determining,  85 
Strength  properties  of  wood,  26,  81 

as  a  beam,  28 

compression,  26 

hardness,  30 

meaning,  26 

nail  holding  power,  30 

of  balanced  boxes,  43 

shearing,   26 

shock    resisting    ability,    22,    30 

stiffness,  30 

tensile,   26 
Structure  of  wood  species,  109 

conifers,    114 

hardwoods,  112 


INDEX 


207 


Styles  of  boxes,  42 

characteristics,  64 

dovetail  boxes,  67 

hardware  type,  66 

lock-corner  boxes,  66 

nailed  boxes,  64 

panel  boxes,  70 

standard  styles,  64 

wirebound  boxes,  67 
Styles  of   crates,  77 
Sugar  maple,  sec  Hard  maple 
Sugar  berry,  see  Hackberry 
Sugar  pine.    Identification,  133 

rules  for  grading,  161 

structure,  123 
Summerwood,  110 
Surfacing  of  boxes,   101 
Swelling  of  wood, .16,  22' 

how  avoided,  23 
Sycamore.    Identification,   129 

structure,   120 


Tamarack.    Structure,   124 

Taste  of  wood,  26 

in  identification,  116 

Tensile  strength  of  wood,  26 

Tensile   strength   of   strapping.    Af- 
fected by  annealing,  60 

Testing  of  boxes  and  creates,  87 
compression-on-an-edge   test,   92 
compression-cornerwise   test,   96 
compression-on-faces  test,  96 
drop-cornerwise  test,  92 
drop-edgewise  test,  92 
drum  test,  91 
information   obtained,   87 
supplementary  tests,  96 

Thickness  of  box  parts,  100 

relation  to  size  of  nailhead,  57 
relation  to  strapping,  61 
relation  to  wood  groups,  103 
variation   allowable,   101 
in  wirebound  boxes,  105 

Thickness   of   crate  parts,   81' 

Thieving,  see  Pilferage 

Three-way-corner  construction.    Box 

66 
crate,  77 

Tie  rods,  sec  Binding  rods 

Traffic  limitations  on  box  design,  74 
85 

Tracheids,  114 

Transportation     hazards,    see    Haz- 
ards. 

Trays.    Use  in  boxes,  76 

Tulip,  see  Poplar,  yellow 


Tupelo.    Rules  for  grading,  157 

structure,   122 
Twisting,   10,  31 

of  plywood,  37 
Tyloses,   112 
Types  of  crate  corner,  77 

U 

Unannealed  strapping,  60 
V 

Veneer.    Availability,  41 

definition,  37 

drying,  36 

method  of  cutting,  37 

plywood,  39 

woods  used  in  box  veneer,  38 
Vermin.    Protection,  76 
Virginia   pine,   see    Southern   yellow 
pine 

W 

Wane,  9 

Warped   lumber.     Use    in   boxes,    46 

use  in  crates,  81 
Warping,   10,   16 

Washers.    Use  on  crate  bolts,  84 
Waste  in  lumber  use,  11 
Waterproof   paper.    Use,   74 
Waterproof  crate  covers,  81 
Weaving.    Resistance,   43 

in  crates,  78 
Webbing  handles,  63 
Wedgelock  ends  in  wirebound  boxes, 

106 

Weight  of  boxes.    How  determined, 
73 

reduced  by  strapping,  60 
Weight  of   wood.    Factors   influenc- 
ing,  15 

how  determined,    15 

how  expressed,  14 

importance,   14 

Western  hemlock.  Identification,  136 
Western    red    cedar.     Identification, 

132 

Western  white   pine.     Identification, 
133 

rules    for  grading,    141 

see  also  Yellow  pine,   Western 
Western    yellow    pine,    see     Yellow 

pine 
White  ash.    Identification,    127 

structure,  119 

White  cedar,  see  Northern  white  ce- 
dar 
White  elm.    Identification,   127 

structure,   119 


208 


INDEX 


White  fir.    Identification,   136 
White  oak.     Identification,  126 

rules  for  grading,  158 

structure,   118 
White  pine.    Structure,   123 

Eastern   identification,    133 
rules    for    grading,    141 

Western    identification,    133 

see  also   Yellow  pine,   Western 
White  spruce.     Identification,   134 
Width  of  pieces,   101 

joints,  43 

stock,  43 

Willow.     Structure,   120 
Wire  bands,  see  Metal  binding 
Wirebound  box,  67 

assembling,   105 

closing,    107 

construction,   104 

grouping  of   woods,   104 

material,   104 

specifications,   103 

with  detached  tops,    107 

with   wedgelock   ends,    105 
Wood  fibers,  113 
Woods    used    in    boxes    and    crates. 

Amount  of  each  species,  2 

availability,   1 

choice,  2 

cost,   1 

choice   in   relation  to  design,  45 

compression    strength,   26 

density,  15 

description,    126 

desirable  qualities,  2 

distribution,   5 

fiber  saturation  point,  16 

fungous  growth,  31 

geographical       distribution      by 
States,  126 

grouping,    100,    104 

hardness,  30 


identification,  115 
kinds,  3 

mechanical   properties,   26 
moisture  content,  15 

see    also    Moisture    content 
nail  holding  power,   15,  30 
nailing  qualities,  51 
odor,  26 

physical  properties,  14 
properties    which    influence    use 

in  box  construction,  14 
resin  content,  15 
salvage  value,  1 
shearing   strength;   26 
shock  resisting  ability,  22,  30 
sources,  5 
species,  2 

specific  gravity,   14 
stiffness,  30 
strength   properties,   26 
structure,   108 
taste,  26 

tensile  strength,  26 
veneer,  38 
weight,  14 
see  also  Lumber 
Worm  holes,    10 

-  effect  on  box   strength,   51 


Yellow   buckeye.     Identification,    132 
Yellow    pine,    Southern.     Identifica- 
tion, 134 

rules  for  grading,   143 
structure,   123 

Western.      Identification,    134 
rules  for  grading,   148 
structure,   123 

Yellow  poplar.    Identification,   131 
rules  for  grading,   150 
structure,   121 


50rn'7,'29 


458422 


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